Travis’ ‘final act’ has always seemed a bit curious to me. Firstly whilst he’s clearly a nutter, it’s a stretch to imagine he’d want to wipe out humanity, and secondly how the hell did he contact the Andromedans?
Like many of Terry Nation's scripts, I try not to look past the gloss for the substance. Travis clearly arrived at Star one in an Andromedan vessel, as hinted by Orac and Vila. The antimatter minefield has been in place for several hundred years, and so clearly the Andromedans somehow breached it and contacted Travis, who promised to find the location of Star One and help remove the rest of it. Hell, are we even sure that WAS Travis? It could've been an Andromedan. After all, he does look slightly different from when we saw him last on Aristo...