Varkan was a Romulan commander, and commanding officer of the Wisdom in an alternate timeline caused when Montgomery Scott rescued James T. Kirk before he could be absorbed into the Nexus, with the USS Enterprise-D following them into the past. Varkan was both feared and respected within his crew.
In 2293, the Wisdom was transporting Supreme Arbiter of the Alliance Sarek to observe the Vortex; Sarek's patience for the mission wore thin and he was about to return to Alliance Prime when Alliance Outpost Number 3 contacted the Wisdom and requested they investigate a mysterious vessel that had appeared from nowhere near the Vortex. When the Wisdom intercepted the vessel, Scott's shuttlecraft Goddard, Varkan was ordered to transport the two Terrans aboard to Interrogation, where Sarek questioned them over Varkan's concerns.
Varkan had to interrupt Sarek's interrogation when the Wisdom picked up a distress call from a lifepod, which contained ex-Alliance Council member Zarcot. Zarcot claimed that his lifepod was all that remained from an incident with the Vortex and asked to be transported aboard before running out of life support. Varkan initially believed there to be no immediate threat to the Cardassian but when it appeared life support was failing, Sarek agreed to the transport. However, it was a ruse to get the Wisdom to lower its shields, allowing a cloaked Cardassian vessel to destroy the ship and its crew. Varkan wanted to return fire and pursue the vessel after the assassination attempt failed, but Sarek forced him to stand down.
Varkan later contacted Sarek to inform him of a fleet-wide alert that requested sightings of Scott, which Sarek had insisted be brought aboard; the Romulan was surprised when Sarek already knew that a vessel named Enterprise had made the request via another Alliance vessel.
After Captain Jean-Luc Picard informed Sarek there was a likely Borg spy aboard the Wisdom, Varkan had all of the crew transported in small groups to the Enterprise; the spy was located and killed, but the Borg Collective began to pursue the Starfleet vessel, and Sarek ordered Varkan not to follow the Enterprise if it fled or to answer their hails. After Sarek accepted Picard's plan of action to return the timeline to its original state, Varkan was ordered, along with all other willing Alliance commanders, to use their vessels to engage a fleet of Borg cubes, giving the Enterprise time to proceed to their destination. (Star Trek novel: Engines of Destiny)
- It is uncertain if a Varkan existed in the primary timeline.