diff --git a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
index a48db75f..d0a1fde9 100644
--- a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
+++ b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
@@ -431,3 +431,7 @@ names the principle that settles it, and is cited as "design 47 G A-n".
   `mesh-broker`'s verbs and sends the chunks itself; the builder's process serves `reserved` and `builder_build`; the
   runner's process serves `review`, `rerun`, `accept` and `cancel`, writing `pipelines` by compare-and-set; the chunk
   subjects go to the process that answers.
+- **A-108** (§630, §214, §406, §516; principle 7) The catch-up is the node agent's: after the restore and the `Apply` of
+  the reverted build, it calls the point's recorded `{tool, arguments}` as that module's tool on its own node through
+  the tool runner, as `holder:node-engine` is granted (§406); `restore-kept` carries the snapshot only. §630's "passes
+  its catch-up to restore-kept" reads "runs its catch-up after it".