Commander Makara is angry at X-Bomber's rescue of Lamia her scientist Caliban comes to the bridge to show her the bionic assassin he has developed to kill F-01 against the Imperial Master's orders. Lamia recovers from her ordeal on X-Bomber weakened and struggling to communicate with Captain Halley on Collinian. X-Bomber detects a deserted spaceship. The pilots visit it in the Dai-X fighter and find nothing there but the Cyborg assassin hides in Legtrack returning with them to X-Bomber. X-Bomber encounters a spherical object in space approaching them. They take evasive action but the sphere follows them at hyper speed and opens fire on the ship. X-Bomber is damaged and launches the Dai-X fighters which immediately combine into the Dai-X robot. With the ship all but empty the Cyborg stalks the corridors finding Lamia's room and attacking her. Kirrara defends her enabling her to sound the alarm summoning Dr Benn who orders PPA to recall Dai-X. Dai-X fires a laser beam from the X crest on it's head destroying the sphere and the pilots set out for X-Bomber. Dr Benn shoots the assassin wounding it, but it makes another attempt to kill her catching Dr Benn with it's serrated claw before he kills it. The pilots return to the ship and X-Bomber resumes it's course for Collinian. Makara is angry at the failure of Caliban's assassin and he begs for one more chance. X-Bomber nears Collinian, and are contacted by Captain Halley but Dr Benn collapses in his chair mortally wounded by poison from the Assassin and die. The pilots vow to continue their mission as Shiro states that there will never be another man that could take the Doctor's place.
Huge, huge episode for the series. You have to start with the ending though: killing one of the lead characters? In sight of his goal? Harsh by itself and very harsh for a children's series. Yes Dr Benn died heroically defending Lamia but you can't help feeling that if he'd sought medical help immediately he might have lived..... I've got some thoughts about the timing of the death too, but that relates to a huge surprise in the next episode so I'll save it till then.
Then we have the series new character Caliban, the silver skinned Imperial Alliance scientist Caliban. He's got a bionic lens covering his right eye but it seems to be a piece of machinery rather than the creature like implants seen on other Imperial Alliance officers. I'm not 100% sure but I think Caliban is another character voiced by Garrick Hagon, previously Captain Carter and now Captain Halley.
The first of Caliban's ball like Death Machines appears in this episode (and the second appears in the next time trailer despite not appearing till the end of the next episode!) which gives us the first opportunity to see Dai-X fighting in space as opposed to on the ground. We've known it can fly since it's first appearance in the Jupiter battle where it forms in the air then lands but this is the first time it's engaged in combat while flying. With the arms stretched out in front it can use the missiles and Super Cannon (pink blasts again) but here it needs to be upright to deploy the constant laser blast from the X shaped crest on it's head - a mini version of X-Impulse? It's the only time we see this weapon used though they;ll be a very similar one in two episodes time.... This is the first time we see the two halves of brain con coming together to form the head of Dai-X: we've previously seen it in two halves as a fighter and then together as a head but not as it transitions through the two states. It's the third time the pilots all wear their space suits (episode 5 & 18) but the fifth time for Shiro (above plus 12 & 14).
This episode is the first to appear on US Video Volume 7: Attack of the Bionic Robot. The back cover here is interesting as it shows Shiro meeting one of the staff at Star Fleet command. An enlarged scene (but smaller image) can be found here (top right) which shows Lee & Hercules in the room too. Publicity image or one cut from the Japanese promotional episode 0, presumed also to be the source of the shot of PPA flying in Braincon with Shiro seen at 2m50s into this video (screenshot here)? Sadly this promo is another item missing from the UK DVD which would have added value to the set.
The bionic assassin segments of the episode (but not the death ball sequences) appear on the UK Video Space Quest for F-01. When I started obtaining Star Fleet episodes on video from people I knew this was one of the first complete episodes I saw. This was also the last episode of Star Fleet to air in the Sunday morning run of episodes in 1983 at around the end of February/start of March (I can't be precise because I don't have airdates for later episodes)
As well as being the last episode in which his character Dr Benn appears, Peter Marinker is credited in the interview by voice director Louis Elman on Star Fleet - The Complete Series as effectively taking over the direction of the final half dozen episodes of the series when Elman is called to another project. Peter Marinker's extensive CV goes right the way back to working on Z-Cars in the 60s and includes an episode of the Professionals which I've seen and own. His first credited voice over work was on Monkey providing a number of supporting roles, although I've seen it claimed he worked on The Water Margin prior to this. This has led to a career in voice over work - if you're watching an English dub of a Japanese Manga production then he's probably involved - but he's also appeared on film in Event Horizon, the Sylvester Stalone Judge Dredd and Love Actually. Dr Benn isn't his only role in Star Fleet, although it's the one he's credited for, as he also provides the voice of the narrator.