Star Trek: The Next Generation – All Good Things [7.25]

Picard finds himself mysteriously moving back and forth between three different eras of his life:  the day when he first came aboard the Enterprise as Captain, far future when he is long-retired, and the “present day.”  In all three time frames he becomes aware of a mysterious anomaly in space that threatens to destroy the universe.  He is also told by Q that he must solve this mystery in order to prove that humanity is worthy to exist. 

Star Trek: The Next Generation – Phantasms [7.6]

Data begins to experience inexplicable nightmares that become waking dreams, and lead him to at one point stab Counselor Troi.  It turns out that Data is observing on a subconscious level parasitic organisms that are normally undetectable to Starfleet officers or technology which are feeding on the crew, and interpreting this information through his dreams.  Using the holodeck, the crew is able to determine what is happening and stop it.

Star Trek: The Next Generation – The Measure of a Man [2.9]

Data is ordered to transfer to the command of a robotics expert who intends to dismantle Data in order to study him and duplicate him.  When Data refuses even to the point of resigning his commission, he becomes the center of a legal battle to determine if he has the rights of a sentient being.