Gul Russol was a Cardassian military officer and one of Odo’s most reliable informants. Russol was executed in 2374, by order of the Cardassian Central Command, when the Cardassian Union joined the Dominion. In early 2375, Weyoun 6 contacted Odo via a coded message, that was supposedly from Russol. It has been suggested by fans that the informant seen in “Improbable Cause” was Russol.