The Metamorph

a.k.a.

"Metamorph" (occasional shortening of name in discussion; also so-labeled on the A&E disk)
2a (in a way in which the Editor frequently counts episodes)
Psychon encounter (in a manner of speaking; but not in an episode)

Intro

1st episode of a revamped second season (Y2), 25th overall. Written by Johnny Byrne. Directed by Charles Crichton.

Summary

An Eagle sent to an apparently lifeless planet is captured by an alien there, Mentor of Psychon, who agrees to return the Alphans, if Alpha leaves Psychon alone. He betrays them and captures the new mission, including John, who discovers Mentor intends to feed Alphan minds to Psyche, a biological computer. Koenig has multiple confrontations with Mentor's metamorphic daughter, Maya, whom he discovers is unaware of Mentor's true intentions. He finally convinces her to check his story; she is horrified by what she finds, and frees the Alphans. John and Maya confront Mentor, Psyche is destroyed, followed by Psychon itself. Mentor remains and dies, despite Maya trying to save him. The Alphans escape, with Maya, welcoming her to join Alpha.

Plot

The Alphans encounter a volcanic "environmental hell" of a planet they think is uninhabited, and send a mineral survey mission on Eagle 1, with Bill Fraser as pilot and Ray Torens on board.
The Eagle is captured in space by an energy weapon sent by an alien named Mentor, of Psychon, who shades his action as defensive.
He and Koenig negotiate the return of the Eagle pilots and some minerals for Alpha, in exchange for Alpha otherwise leaving Psychon alone. Alpha sends Eagle 4, with John Koenig, Helena Russell, Alan Carter, and Lew Picard on board. Mentor sends a spaceship, supposedly with Fraser and Torens on it. He betrays them, trying to capture them with his empty ship, and then transforming the latter into an energy weapon, which captures the second mission, and dragging the Eagle onto the floor of an inactive volcano containing a spaceship graveyard.
Meanwhile, Mentor drains the mind of Torens.
Those on Eagle 4 leave it and enter a cavern, and discover brain-damaged beings, including Torens, in a mine. An image of Mentor appears in the mine. Lew, trying to shoot past it with a laser rifle, is vaporized. The others flee, but are captured.

John wakes up to find himself in a cell, being stared at by a lioness, who transforms into a beautiful alien woman named Maya, Mentor's metamorphic daughter, who escorts him to meet Mentor.
Mentor dismisses Maya, and the Commander hears Mentor's sinister plans on feeding more Alphan minds to a biological computer named Psyche. Mentor threatens to drain the minds of Helena, Alan, and Bill, using it -- and an offer that those three and John can settle on Psychon -- in an attempt to extort(?) John into drawing the other Alphans off-base, where Mentor can capture them. John seems to relent (much to the shock of the others), and orders a reluctant Tony to start sending Eagles to Psychon under Directive Four.
This however, actually turns out to be a coded signal to attack Psychon. Tony sends an nuclear-packed Eagle in an attempt to do so, but it is discovered as such by Maya and Mentor, and destroyed.
However, this precipitates Maya into another confrontation with John. She believes John to be lying, but he finally convinces her to check his story anyway. She is horrified by what she discovers in the caverns, and again when she returns to the cell and finds Mentor is beaming an image of his weapons blasting away at Alpha. She frees the remaining Alphans.
Maya and John confront Mentor. John starts destroying Psyche, whose systems are tied into the planet, which then proceeds to self-destruct. Mentor remains, but pleads with Keonig to save Maya. She fights to reach Mentor, but he dies, and Koenig brings Maya to the Eagle to flee Psychon, which is exploding, and is soon destroyed.
Maya is welcomed as a friend, to join Alpha as a new member.

Details

Bill Fraser is knocked unconscious trying to warn Alpha of the danger everyone is in. Mentor declares Bill to be feverish, and to send a medical officer, which is what brings Dr. Russell to Psychon. In taking a hit, Bill probably saves himself from being immediately brain-drained, to which his still-conscious compatriot, Ray Torens is soon subjected.
Mentor offers to provide some minerals if they send a "scientific officer" to discuss the needs. That results in Lew being sent; though it is not necessarily clear Lew is actually the Science Officer at that point.
Bill Fraser and Annette Fraser were married only two months before. She is in considerable distress at times, including fainting on Bill's initial capture, and beating Tony's chest after he orders the nuclear Eagle to attack Psychon, with Bill and all the others still there. Yet she is also usually quick to recover her composure.
At one point, Bill, in a cell with the other Alphans, looks at a picture of his wife, Annette.
Tony is in temporary command of Alpha while John, Alan, and Helena are away. Sandra Benes is his second through that stretch.
Sandra tries to argue around Directive Four, but the "coded signal" is mandatory, and Tony knows everyone must be in terrible danger. If Directive Four had succeeded as specified, Tony would have been left in command, with Sandra as the only remaining officer. This was soon after other key personnel were presumably lost, namely at least: Paul Morrow, Victor Bergman, David Kano.
Directive Four does indirectly succeed. Though the Eagle is destroyed, the attempt disgusts Maya, and prompts her to confront John, allowing him another chance -- this time successful -- to convince her to check on what her father has really been doing for years.
In trying to save her father, who won't leave Psychon as it dies, Maya fights John, initially in her humanoid form, then in progressively stronger animal forms, until she slams John against a wall. However, by the time she is free, Mentor is dead, and she can only revert and sob as everything she knew is being destroyed around her.