Warning: one of these groups is almost impossible for those of us in the UK, as it features a product exclusively available in the US and Canada.

Argh, I've been sitting on a grid with two of these groups and the same false group for ages! Nice to see the same idea done well. I think the 2^6 clue is a bit mean, since it requires an extra step of logic which none of its groupmates do.

Apologies. I should have researched that a bit more. I just assumed it was in the UK.

I've heard of 3 Musketeers and I'm in the UK... but then I've only heard of it from 90s US comic books.