After celebrating the well-deserved promotion of Oliver Weston to Lieutenant Commander, the crew heads off on the newly repaired USS Drake to activate the last communication beacon in the Ishkarian sensor array.
A flash of green light shifts through the ship causing multiple explosions and power failures just after the aged and inoperative beacon comes into view. As the crew scrambles to save lives and repair critical systems, Lieutenants Pandora and Reed follow a chronoton radiation power signal to the weapons pod and unearth the source – a time-travel device with the DNA fingerprint of Professor Arnold.
Meanwhile, the bridge crew works to piece together information as the communications beacon, ancient only seconds ago, looms onscreen, suddenly appearing quite new. They discover that they have travelled backwards in time roughly 2500 years, to a time before the Ishkarian home world catastrophically broke apart into the shards of the modern age.
In addition, Lt. Stennes detects an ion trail identical to that of the Drake. Coupled with the telepathic abilities of the Vulcan officers, the crew ascertain that Arnold sent a duplicate Drake back as well, roughly three days before the current date and time. Realizing the delicacy of the situation, the importance of protecting the timeline becomes paramount. As an injured Captain Rogers breaks the crew into teams, they prepare for the moment when the two Drakes meet, the infiltration of Ishkarian society becomes necessary, and Professor Arnold’s secret is revealed.