[Anonymouse]

Anyone else remember him in UFO? He played Paul Roper, a systems specialist working on SID - he was being blackmailed by the Aliens, who were threatening his gorgeous young wife Carol (Sonia Fox) unless he fed certain data into SID for processing, memorised the results and passed them to an agent. It turned out to be a flight path (hence the episode's title) to enable a UFO to approach Moonbase with the sun behind it, coinciding with heavy sunspot activity so neither Moonbase nor the Interceptors could track it.

SHADO's only hope? Paul Roper, with only a spacesuit, polarised visor and a rocket launcher. He intercepted it, but his suit was punctured and he passed out, suffocating before a Moon Mobile could reach him.

"I don't need a volunteer, Alec."
"You mean Roper? And I suppose you used this to twist his arm!" Alec Freeman growls, shoving a photo showing a dead Carol (the agent was sent to kill her anyway) across the desk.
"I didn't have to," Ed Straker replies, "he's doing it to even the score."
"And when are you going to tell him?"
"Maybe he'll never need to know..."

And he didn't. Great episode, well acted by all.