Voord
The Voord were either a species, a political faction or a cult of renegade scuba divers on Marinus. In either case, they were totally badass. Most importantly, though, they wore full-body, black ninja scuba outfits and were unjustifiably good at blending into their surroundings. So much so, in fact, that we used to refer to anyone “hiding” in plain sight as “Voord-hiding”. That was a good expression. We should bring it back.
A little further along the fourth dimension, we return to Doctor Who as presented in TWO dimensions.
The Doctor & Co arrive on Marinus and are blackmailed by Arbitan to go on a suicide mission to retrieve the five titular micro-circuit keys.