A Ferengi who hijacked a holographic Reginald Barclay sent to Voyager, in a plan to steal Seven of Nine's nanoprobes.
Gegis is the Ferengi behind the plot in Inside Man. Working with Barclay's girlfriend Leosa, he intercepts the holographic Barclay that the Pathfinder Project sends to Voyager and reprograms it, so that it guides the ship toward a geodesic fold that would bring it home while killing the crew, leaving Seven of Nine's Borg nanoprobes for the taking.
The real Barclay uncovers the scheme with Deanna Troi's help. With help unlikely to arrive in time, he poses as the hologram and frightens the Ferengi into abandoning the plot, and Voyager is saved.