diff --git a/static/css/notes2.css b/static/css/notes2.css
index b4d7e02..743b4b3 100644
--- a/static/css/notes2.css
+++ b/static/css/notes2.css
@@ -92,7 +92,7 @@ button {
 			border-right: none;
 		}
 
-		n2-sidebar {
+		n2-tree {
 			display: none;
 
 		}
@@ -164,7 +164,7 @@ button {
 
 	border-right: 1px solid var(--line-color);
 
-	n2-sidebar {
+	n2-tree {
 		.el-treenodes {
 			margin: 24px 32px 32px 32px;
 		}
@@ -508,7 +508,7 @@ dialog.op {
 	}
 
 	#tree {
-		n2-sidebar {
+		n2-tree {
 			.el-treenodes {
 				height: calc(100vh - 64px - 64px);
 				margin: 0px;
diff --git a/static/js/app.mjs b/static/js/app.mjs
index 7a9ac52..b444140 100644
--- a/static/js/app.mjs
+++ b/static/js/app.mjs
@@ -1,21 +1,16 @@
 import { ROOT_NODE } from 'node_store'
 import { CustomHTMLElement } from './lib/custom_html_element.mjs'
-import { N2Sidebar } from 'sidebar'
+import { N2Tree } from 'tree'
 import { Node } from 'node'
 
 export class App {
 	constructor() {// {{{
 		this.currentNode = null
-		this.sidebar = new N2Sidebar()
+		this.tree = new N2Tree()
 		this.crumbs = new N2Crumbs()
 		this.crumbsElement = document.getElementById('crumbs')
 		this.nodeUI = document.getElementById('note')
-		this.showNodeEventSequence = new ShowNodeEventSequence() // discard all GO_TO_NODE events
 
-		this.sidebar.render().then(sidebar => {
-			document.getElementById('tree').append(sidebar)
-			document.getElementById('tree-nodes')?.focus()
-		})
 
 		_mbus.subscribe('TREE_TRUNK_FETCHED', async () => {
 			// Subscribing to the start node existing after the tree trunk is
@@ -23,8 +18,11 @@ export class App {
 			// root node itself, and the root node should be selected in the tree
 			// after it is rendered when the site is shown without UUID in the URL.
 			const startNode = await this.getStartNode()
+			_mbus.subscribe(`NODE_COMPONENT_EXIST_${startNode.UUID}`, () => {
+				this.goToNode(startNode.UUID, false, false)
+			})
 
-			document.getElementById('tree').append(await this.sidebar.render())
+			document.getElementById('tree').append(await this.tree.render())
 			document.getElementById('tree-nodes')?.focus()
 
 			if (startNode.UUID == ROOT_NODE)
@@ -87,7 +85,7 @@ export class App {
 				if (document.activeElement.id === 'tree-nodes') {
 					this.nodeUI.takeFocus()
 				} else {
-					this.sidebar.focus()
+					this.tree.focus()
 				}
 				break
 
@@ -186,38 +184,17 @@ export class App {
 		node.reset() // any modifications are discarded.
 
 		this.currentNode = node
-		this.sidebar.setSelected(node, dontExpand)
+		this.tree.setSelected(node, dontExpand)
 
 		const ancestors = await nodeStore.getNodeAncestry(node)
+		_mbus.dispatch('CRUMBS_SET', ancestors, () => this.crumbsElement.replaceChildren(this.crumbs.render()))
+		_mbus.dispatch('NODE_UI_OPEN', node)
+		_mbus.dispatch('NODE_UNMODIFIED')
+		_mbus.dispatch('TREE_EXPANSION', { expand: false, when: 'narrow' })
 
 		// Scrolls node into view.
-		// makeVisible normally expands all ancestor nodes to make the whole chain visible.
-		// This is a bad idea when quickly navigating the tree, since the arrow navigation
-		// has collapsed nodes which the event calling goToNode can come to undo, if the
-		// event processing lags behind.
-		await this.sidebar.makeVisible(node, ancestors, dontExpand)
-
-		_mbus.dispatch('CRUMBS_SET', ancestors, () => this.crumbsElement.replaceChildren(this.crumbs.render()))
-		_mbus.dispatch('NODE_UI_OPEN', { node, eventSequence: this.showNodeEventSequence.next() })
-		_mbus.dispatch('TREE_EXPANSION', { expand: false, when: 'narrow' })
-		_mbus.dispatch('NODE_UNMODIFIED')
+		this.tree.makeVisible(node)
 	}//}}}
-	pageIsVisible(page) {// {{{
-		let classList = document.querySelector('#main-page').classList
-		return classList.contains(page)
-	}// }}}
-}
-
-class ShowNodeEventSequence {
-	constructor() {
-		this.seq = 0
-	}
-	next() {
-		return ++this.seq
-	}
-	current() {
-		return this.seq
-	}
 }
 
 class N2Crumbs extends CustomHTMLElement {
diff --git a/static/js/node_store.mjs b/static/js/node_store.mjs
index 3bd2701..bd2a331 100644
--- a/static/js/node_store.mjs
+++ b/static/js/node_store.mjs
@@ -199,7 +199,9 @@ export class NodeStore {
 				}
 
 				Promise.all(hasChildrenPromises)
-					.then(() => resolve(nodes))
+					.then(() => {
+						resolve(nodes)
+					})
 			}
 			req.onerror = (event) => reject(event.target.error)
 		})
diff --git a/static/js/page_history.mjs b/static/js/page_history.mjs
index 44061f6..b03c810 100644
--- a/static/js/page_history.mjs
+++ b/static/js/page_history.mjs
@@ -80,11 +80,8 @@ export class N2PageHistory extends CustomHTMLElement {
 
 		})
 
-		_mbus.subscribe('SHOW_PAGE', async (event) => {
-			if(event.detail.data.page != 'history')
-				return
-
-			await this.useNode(_app.nodeUI.node)
+		_mbus.subscribe('NODE_UI_OPEN', async (event) => {
+			await this.useNode(event.detail.data)
 			this.render()
 		})
 
diff --git a/static/js/page_node.mjs b/static/js/page_node.mjs
index a2ebf52..9a82b90 100644
--- a/static/js/page_node.mjs
+++ b/static/js/page_node.mjs
@@ -42,8 +42,7 @@ export class N2PageNodeUI extends CustomHTMLElement {
 		this.marked = new MarkedPosition()
 
 		_mbus.subscribe('NODE_UI_OPEN', event => {
-			console.log(event.detail.data.eventSequence, _app.showNodeEventSequence.current())
-			this.node = event.detail.data.node
+			this.node = event.detail.data
 			this.showMarkdown(true)
 			this.render()
 		})
@@ -377,6 +376,10 @@ export class Node {
 			this.Children[i]._parent = this
 		}
 
+		// Notify the tree that all children are fetched and ready to process.
+		//_notes2.current.tree.fetchChildrenOn(this.UUID)
+		_mbus.dispatch(`NODE_CHILDREN_FETCHED_${this.UUID}`)
+
 		return this.Children
 	}//}}}
 	setHasChildren(v) {// {{{
diff --git a/static/js/sidebar.mjs b/static/js/tree.mjs
similarity index 86%
rename from static/js/sidebar.mjs
rename to static/js/tree.mjs
index d1263a3..6443455 100644
--- a/static/js/sidebar.mjs
+++ b/static/js/tree.mjs
@@ -1,6 +1,7 @@
 import { ROOT_NODE } from 'node_store'
 import { CustomHTMLElement } from './lib/custom_html_element.mjs'
 import { Color, Solver } from './lib/css_colorize.mjs'
+import { Node } from './page_node.mjs'
 
 // TreeExpandedHandler is responsible for collapsing or expanding
 // the node tree, wide view or narrow "mobile" view.
@@ -58,12 +59,12 @@ class TreeExpansionHandler {// {{{
 	}
 }// }}}
 
-export class N2Sidebar extends CustomHTMLElement {
+export class N2Tree extends CustomHTMLElement {
 	static {// {{{
 		this.tmpl = document.createElement('template')
 		this.tmpl.innerHTML = `
 			<style>
-				n2-sidebar {
+				n2-tree {
 					#logo {
 						display: grid;
 						grid-template-columns: 1fr min-content;
@@ -144,21 +145,24 @@ export class N2Sidebar extends CustomHTMLElement {
 			treenode.render(true)
 		})
 
+		this.populateFirstLevel()
+
 		/* XXX - set color */
 		let color = new Color(0x80, 0x00, 0x33)
 		let solver = new Solver(color)
 		let result = solver.solve()
-		console.log(result.filter)
+		// console.log(result.filter)
 	}// }}}
 	async render() {// {{{
 		if (this.rendered)
 			alert('Tree should only be rendered once.')
 
+
 		this.expandedNodes[ROOT_NODE] = true
 		const startnode = await nodeStore.get(ROOT_NODE)
 		const starttreenode = new N2TreeNode(this, startnode, null)
 		this.treeNodeComponents[startnode.UUID] = starttreenode
-		this.elTreenodes.appendChild(await starttreenode.render())
+		this.elTreenodes.appendChild(starttreenode.render())
 
 		this.rendered = true
 		return this
@@ -170,6 +174,27 @@ export class N2Sidebar extends CustomHTMLElement {
 		this.elTreenodes.replaceChildren()
 		this.populateFirstLevel()
 	}// }}}
+	populateFirstLevel() {//{{{
+		nodeStore.get(ROOT_NODE)
+			.then(node => node.fetchChildren())
+			.then(children => {
+				this.treeNodeComponents = {}
+				this.treeTrunk = []
+				for (const node of children) {
+					// The root node isn't supposed to be shown in the tree.
+					if (node.UUID === ROOT_NODE)
+						continue
+					if (node.ParentUUID === ROOT_NODE)
+						this.treeTrunk.push(node)
+				}
+				_mbus.dispatch('TREE_TRUNK_FETCHED')
+			})
+			.catch(e => {
+				console.error(e)
+				console.log(e.type, e.error)
+				alert(e.error)
+			})
+	}//}}}
 	getNodeExpanded(UUID) {//{{{
 		if (this.expandedNodes[UUID] === undefined)
 			this.expandedNodes[UUID] = false
@@ -224,8 +249,6 @@ export class N2Sidebar extends CustomHTMLElement {
 			// Holding shift down does it recursively.
 			case Space:
 			case 'Enter':
-				if (n.UUID === ROOT_NODE)
-					return
 				const expanded = this.getNodeExpanded(n.UUID)
 				if (event.shiftKey) {
 					this.recursiveExpand(n, !expanded)
@@ -279,7 +302,7 @@ export class N2Sidebar extends CustomHTMLElement {
 			return
 
 		const expanded = this.getNodeExpanded(n.UUID)
-		if (expanded && n.hasChildren() && n.UUID !== ROOT_NODE) {
+		if (expanded && n.hasChildren()) {
 			this.setNodeExpanded(n, false)
 			return
 		}
@@ -429,27 +452,26 @@ export class N2Sidebar extends CustomHTMLElement {
 		if (!state)
 			await this.setNodeExpanded(node, false)
 	}//}}}
-	async makeVisible(node, providedAncestors, dontExpand) {// {{{
+	async makeVisible(node) {// {{{
 		const treenode = this.treeNodeComponents[node.UUID]
 
-		if (!dontExpand) {
-			const ancestors = providedAncestors || await nodeStore.getNodeAncestry(node)
-			for (const ancestor of ancestors.reverse()) {
-				this.setNodeExpanded(ancestor, true)
-			}
+		const ancestors = await nodeStore.getNodeAncestry(node)
+		for (const ancestor of ancestors.reverse()) {
+			this.setNodeExpanded(ancestor, true)
 		}
 
+		// The ROOT_NODE for example hasn't got a treenode.
 		treenode?.scrollIntoView({ block: 'nearest' })
 	}// }}}
 }
-customElements.define('n2-sidebar', N2Sidebar)
+customElements.define('n2-tree', N2Tree)
 
 export class N2TreeNode extends CustomHTMLElement {
 	static {// {{{
 		this.tmpl = document.createElement('template')
 		this.tmpl.innerHTML = `
 			<style>
-				n2-sidebar:focus-within {
+				n2-tree:focus-within {
 					.el-name {
 						&.selected {
 							span {
@@ -481,48 +503,55 @@ export class N2TreeNode extends CustomHTMLElement {
 		`
 	}// }}}
 
-	constructor(sidebar, node, parent) {//{{{
+	constructor(tree, node, parent) {//{{{
 		super()
 		this.classList.add('node')
 
-		this.sidebar = sidebar
+		this.tree = tree
 		this.node = node
 		this.parent = parent
 
 		this.children_populated = false
 		this.rendered = false
 
-		this.elExpandToggle.addEventListener('click', () => this.sidebar.setNodeExpanded(this.node, !this.sidebar.getNodeExpanded(this.node.UUID)))
+		this.elExpandToggle.addEventListener('click', () => this.tree.setNodeExpanded(this.node, !this.tree.getNodeExpanded(this.node.UUID)))
 		this.elName.addEventListener('click', () => _mbus.dispatch('TREE_NODE_SELECTED', this.node))
 
+		_mbus.subscribe(`NODE_CHILDREN_FETCHED_${node.UUID}`, () => {
+			this.render(true)
+		})
+
 		_mbus.subscribe(`NODE_EXPAND_${node.UUID}`, _state => {
 			this.render(true)
 		})
-	}// }}}
-	async fetchChildren(force_fetch) {//{{{
-		if (this.children_populated && !force_fetch)
-			return
 
+		if (this.node.Level === 0 || this.tree.getNodeExpanded(this.node.UUID))
+			this.fetchChildren()
+	}// }}}
+	async fetchChildren() {//{{{
 		await this.node.fetchChildren()
 		this.children_populated = true
 	}//}}}
-	async render(force_update, force_refetch_children) {//{{{
+	render(force_update) {//{{{
 		if (this.rendered && force_update !== true)
 			return this
 
-		if (this.sidebar.getNodeExpanded(this.node.UUID))
-			await this.fetchChildren()
+		// Fetch the next level of children if the parent tree node is expanded and our children thus will be visible.
+		const expanded = this.node.hasChildren() && this.tree.getNodeExpanded(this.node.UUID)
 
-		// Update the name and selected status.
+		if (!this.children_populated && this.tree.getNodeExpanded(this.parent?.node.UUID)) {
+			this.node.fetchChildren().then(() => this.children_populated = true)
+		}
+
+		// Update the name and selected status
 		this.elName.querySelector('span').innerText = this.node.get('Name')
 
-		if (this.sidebar.isSelected(this.node))
+		if (this.tree.isSelected(this.node))
 			this.elName.classList.add('selected')
 		else
 			this.elName.classList.remove('selected')
 
 		// Update expansion state
-		const expanded = this.node.hasChildren() && this.sidebar.getNodeExpanded(this.node.UUID)
 		if (expanded) {
 			this.elChildren.classList.add('expanded')
 			this.elChildren.classList.remove('collapsed')
@@ -536,27 +565,27 @@ export class N2TreeNode extends CustomHTMLElement {
 			this.setImgSrc(this.elExpand, `/images/${window._VERSION}/icon_home.svg`)
 		else if (!this.node.hasChildren())
 			this.setImgSrc(this.elExpand, `/images/${window._VERSION}/leaf.svg`)
-		else if (this.sidebar.getNodeExpanded(this.node.UUID))
+		else if (this.tree.getNodeExpanded(this.node.UUID))
 			this.setImgSrc(this.elExpand, `/images/${window._VERSION}/expanded.svg`)
 		else
 			this.setImgSrc(this.elExpand, `/images/${window._VERSION}/collapsed.svg`)
 
 		// Should children be rendered?
+		this.elChildren.innerHTML = ''
 		let children = []
 		if (expanded)
 			children = this.node.Children.map(node => {
-				let treenode = this.sidebar.treeNodeComponents[node.UUID]
+				let treenode = this.tree.treeNodeComponents[node.UUID]
 				if (treenode === undefined) {
-					treenode = new N2TreeNode(this.sidebar, node, this)
-					this.sidebar.treeNodeComponents[node.UUID] = treenode
+					treenode = new N2TreeNode(this.tree, node, this)
+					this.tree.treeNodeComponents[node.UUID] = treenode
+					_mbus.dispatch(`NODE_COMPONENT_EXIST_${node.UUID}`)
 				}
 				return treenode
 			})
 
-		const renderedChildren = []
 		for (const c of children)
-			renderedChildren.push(await c.render())
-		this.elChildren.replaceChildren(...renderedChildren)
+			this.elChildren.appendChild(c.render())
 
 		this.rendered = true
 		return this
diff --git a/views/layouts/main.gotmpl b/views/layouts/main.gotmpl
index c5fbead..ead95a9 100644
--- a/views/layouts/main.gotmpl
+++ b/views/layouts/main.gotmpl
@@ -15,7 +15,7 @@
 				"crypto":     "/js/{{ .VERSION }}/crypto.mjs",
 				"node_store": "/js/{{ .VERSION }}/node_store.mjs",
 				"node":       "/js/{{ .VERSION }}/page_node.mjs",
-				"sidebar":    "/js/{{ .VERSION }}/sidebar.mjs"
+				"tree":       "/js/{{ .VERSION }}/tree.mjs"
 			}
 		}
 		</script>