A member of the Devore race, Kashyk was one of several inspectors who frequently harassed
Voyager's Captain Janeway with his searches. Kashyk grew quite familiar with the crew and with their captain, to the point where, on one inspection, he made himself at home in Janeway's ready room and replicated some coffee.
As a member of the Devore Imperium, Kashyk considers all "gaharay," or strangers, to be suspect, and vessels in their space must be searched. They are looking for Brenari, telepaths, who they believe break the cardinal rule of trust by reading minds.
For reasons not immediately known to Janeway, Kashyk hailed the captain and sought asylum on her ship. He revealed that he was aware of the refugees she hid, and that the wormhole Voyager seeks is a trap to catch ships smuggling telepaths.
Kashyk made good on his promise to aid Janeway in avoiding Devore detection; he provided the captain with intel regarding the location of Devore ships and means of safe passage. Despite the valuable information Kashyk provided, Janeway kept him under a watchful eye. And for good reason: Kashyk pretended to be Janeway's ally, in order to learn both the location of the wormhole and the secret regarding Voyager's Brenari cargo.
Following his revelation, Kashyk ordered that the wormhole be destroyed. A photon torpedo is fired - but nothing happens. Kashyk then realized that it was he who has been duped. The real wormhole was in another location, and the refugees used it as safe passage via shuttles.
Kashyk, not wanting the failure on his record, failed to report the incident and allowed Voyager to resume its course.
