Stardate: 43807.4. A nervous and insecure officer, Lt. Reginald Barclay, places the Enterprise in great danger when he neglects his duties in Engineering, and instead spends his time acting out his fantasies on the holodeck.

Stardate: 44704.2. An alien probe transforms Barclay from a shy, awkward character into an arrogant super-genius who is able to interface with the Enterprise's computer through the holodeck.

Stardate: 46041.1. Lt. Barclay's fear of using transporters is eerily justified when he sees bizarre aliens within the transporter beam.

Stardate: 46424.1. While performing holodeck maintenance, Barclay accesses the stored hologram of Professor Moriarty, who wreaks havoc on board the Enterprise.

Stardate: 47653.2. Upon returning from an away mission, Picard and Data find the ship drifting in space, and the crew de-evolving into their animal ancestors.