diff --git a/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor b/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor
index 1883faa..8bedc93 100644
--- a/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor
+++ b/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor
@@ -52,7 +52,14 @@
                 View this execution in the Audit Log
             </a>
         </div>
-        <ExecutionTree Nodes="_nodes" ArrivedFromExecutionId="_executionId.Value" />
+        <ExecutionTree Nodes="_nodes" ArrivedFromExecutionId="_executionId.Value"
+                       OnNodeActivated="HandleNodeActivated" />
+
+        @* Double-clicking a tree node raises OnNodeActivated, which opens this
+           modal for that execution. The modal renders nothing while IsOpen is
+           false, so it is safe to place unconditionally here. *@
+        <ExecutionDetailModal ExecutionId="_modalExecutionId" IsOpen="_modalOpen"
+                              OnClose="HandleModalClose" />
     }
     else
     {
diff --git a/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor.cs b/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor.cs
index 84ac269..b760939 100644
--- a/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor.cs
+++ b/src/ScadaLink.CentralUI/Components/Pages/Audit/ExecutionTreePage.razor.cs
@@ -40,6 +40,15 @@ public partial class ExecutionTreePage
     private bool _loading;
     private string? _error;
 
+    // Execution-Tree Node Detail Modal feature (Task 4) — state backing the
+    // <ExecutionDetailModal>. A double-click on a tree node sets
+    // _modalExecutionId + flips _modalOpen true; the modal loads that
+    // execution's audit rows on the closed → open transition. _modalOpen is the
+    // visibility gate — _modalExecutionId is left intact across a close (it is
+    // harmless while the modal is hidden and avoids a flicker if reopened).
+    private Guid? _modalExecutionId;
+    private bool _modalOpen;
+
     protected override async Task OnInitializedAsync()
     {
         _executionId = ParseExecutionId();
@@ -90,4 +99,22 @@ public partial class ExecutionTreePage
             _loading = false;
         }
     }
+
+    /// <summary>
+    /// Raised by <c>ExecutionTree</c> (bubbled up from a node double-click) with
+    /// the activated node's <c>ExecutionId</c>. Opens the
+    /// <c>ExecutionDetailModal</c> for that execution — the modal loads its
+    /// audit rows on the closed → open transition.
+    /// </summary>
+    private void HandleNodeActivated(Guid executionId)
+    {
+        _modalExecutionId = executionId;
+        _modalOpen = true;
+    }
+
+    /// <summary>
+    /// Raised by <c>ExecutionDetailModal</c> when the user dismisses it. Flips
+    /// the visibility gate closed; <see cref="_modalExecutionId"/> is left as-is.
+    /// </summary>
+    private void HandleModalClose() => _modalOpen = false;
 }
diff --git a/tests/ScadaLink.CentralUI.Tests/Pages/ExecutionTreePageTests.cs b/tests/ScadaLink.CentralUI.Tests/Pages/ExecutionTreePageTests.cs
index c69d10b..16b29c3 100644
--- a/tests/ScadaLink.CentralUI.Tests/Pages/ExecutionTreePageTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Pages/ExecutionTreePageTests.cs
@@ -7,7 +7,9 @@ using Microsoft.AspNetCore.Components.Authorization;
 using Microsoft.Extensions.DependencyInjection;
 using NSubstitute;
 using ScadaLink.CentralUI.Services;
+using ScadaLink.Commons.Entities.Audit;
 using ScadaLink.Commons.Types.Audit;
+using ScadaLink.Commons.Types.Enums;
 using ScadaLink.Security;
 using ExecutionTreePage = ScadaLink.CentralUI.Components.Pages.Audit.ExecutionTreePage;
 
@@ -111,6 +113,68 @@ public class ExecutionTreePageTests : BunitContext
         _queryService.DidNotReceive().GetExecutionTreeAsync(Arg.Any<Guid>(), Arg.Any<CancellationToken>());
     }
 
+    [Fact]
+    public void DoubleClickTreeNode_OpensExecutionDetailModal()
+    {
+        var root = Guid.Parse("33333333-3333-3333-3333-333333333333");
+        var child = Guid.Parse("44444444-4444-4444-4444-444444444444");
+        _queryService = Substitute.For<IAuditLogQueryService>();
+        _queryService.GetExecutionTreeAsync(child, Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<ExecutionTreeNode>>(new List<ExecutionTreeNode>
+            {
+                Node(root, null),
+                Node(child, root),
+            }));
+        // The modal loads the double-clicked execution's audit rows on open.
+        _queryService.QueryAsync(Arg.Any<AuditLogQueryFilter>(), Arg.Any<AuditLogPaging?>(), Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<AuditEvent>>(Array.Empty<AuditEvent>()));
+        // AuditEventDetail (reachable from the modal) owns a clipboard interop call.
+        JSInterop.Mode = JSRuntimeMode.Loose;
+
+        var cut = RenderPage($"executionId={child}", "Admin");
+
+        // The modal is absent until a node is activated.
+        Assert.Empty(cut.FindAll("[data-test=\"execution-detail-modal\"]"));
+
+        var body = cut.Find($"[data-test=\"tree-node-{child}\"] .execution-tree-body");
+        body.DoubleClick();
+
+        cut.WaitForAssertion(() =>
+            Assert.NotEmpty(cut.FindAll("[data-test=\"execution-detail-modal\"]")));
+        _queryService.Received().QueryAsync(
+            Arg.Is<AuditLogQueryFilter>(f => f.ExecutionId == child),
+            Arg.Any<AuditLogPaging?>(),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public void ClosingExecutionDetailModal_HidesIt()
+    {
+        var root = Guid.Parse("55555555-5555-5555-5555-555555555555");
+        var child = Guid.Parse("66666666-6666-6666-6666-666666666666");
+        _queryService = Substitute.For<IAuditLogQueryService>();
+        _queryService.GetExecutionTreeAsync(child, Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<ExecutionTreeNode>>(new List<ExecutionTreeNode>
+            {
+                Node(root, null),
+                Node(child, root),
+            }));
+        _queryService.QueryAsync(Arg.Any<AuditLogQueryFilter>(), Arg.Any<AuditLogPaging?>(), Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<AuditEvent>>(Array.Empty<AuditEvent>()));
+        JSInterop.Mode = JSRuntimeMode.Loose;
+
+        var cut = RenderPage($"executionId={child}", "Admin");
+
+        cut.Find($"[data-test=\"tree-node-{child}\"] .execution-tree-body").DoubleClick();
+        cut.WaitForAssertion(() =>
+            Assert.NotEmpty(cut.FindAll("[data-test=\"execution-detail-modal\"]")));
+
+        cut.Find("[data-test=\"execution-detail-close\"]").Click();
+
+        cut.WaitForAssertion(() =>
+            Assert.Empty(cut.FindAll("[data-test=\"execution-detail-modal\"]")));
+    }
+
     [Fact]
     public void ExecutionTreePage_HasOperationalAuditAuthorizeAttribute()
     {