Dune: Imperium – Uprising · Board game rules
Can three agents be at the same location?
Quick answer
No — normally only one Agent can occupy a board space at a time, though Infiltrate (recalling a Spy) lets you send your own Agent there anyway.
Details
Each board space can hold only one Agent at a time; you can't send an Agent to a space that already has one occupying it [p.9 — Player Turn - Agent Turn]. This restriction applies regardless of which player placed the first Agent there.
The one exception is the Infiltrate ability tied to Spies: if you wish to send an Agent to a board space occupied by another player's Agent, you may recall your own Spy from a connected observation post to ignore that opponent's Agent and place yours there anyway [p.11 — Spies]. This doesn't remove the other player's Agent — it simply lets you send yours to the same space, effectively allowing two Agents (yours and an opponent's) to occupy it simultaneously.
Watch out: Infiltrate only lets you bypass another player's Agent using your own Spy — you can't use it to let a third Agent join if two Agents from other players are somehow already there, since only one Agent can be blocked/ignored per Infiltrate use, and normal placement rules still prevent more than one Agent per space outside of this specific interaction.