A fairly tropey time travel story, complete with Marty McFly-esc dissappearing, overall this really was just some dumb fun.

I like that it's 1963 for the fun little Classic Who reference, and everything that this is setting up actually seems pretty intriguing with them recognising one of the spies looking familiar (sidenote - most obvious spies I've seen, even in Kids TV), and the russian spy stuff seeming like it'll have an impact on the present day of the story (is the reason the present day stuff is like it is because of USSR Spies???)

I like the kids not knowing about the past so they're learning as they're there, I like the opening scene with Starkey being serious talking about needing to destroy K9 and then pulling back for it to be a chess match, I like the misdirect where you think they've send Darius back and then find out that it's his great granddad (spatial genetic multiplicity?), and I like Gryphen and June's interactions back in the future.

There's some things that don't really make sense: If the people they proved Darius' Great Granddad's innocence to were both Russians, why did they let him go after they left? How did they not have any impact on the future with everything they did? But eh, it's small things I'm not too fussed about and could be explained away easily, doesn't take away too much from an episode I really enjoyed