diff --git a/steward/static/chart-marks.js b/steward/static/chart-marks.js
index aa4568d..d492777 100644
--- a/steward/static/chart-marks.js
+++ b/steward/static/chart-marks.js
@@ -60,7 +60,8 @@
   // Fetch marks from `url` and put them on each chart, redrawing it; `note`
   // (an element, optional) says in words how many there are.
   window.stewardMarkCharts = function (url, charts, note) {
-    fetch(url, { credentials: 'same-origin' })
+    // A deadline, so a slow answer leaves the charts unmarked rather than waiting on.
+    fetch(url, { credentials: 'same-origin', signal: AbortSignal.timeout(10000) })
       .then(function (r) { return r.ok ? r.json() : { marks: [] }; })
       .then(function (body) {
         var marks = body.marks || [];