Two Knights and a Queen

Technically, it would be difficult to fail this mate problem, as there were 4 or 5 alternatives given in Chess Tempo.

However, I was please to solve it correctly, so only discovered the "alts" afterwards.

This was something that just had to be mate, given the position, but I don't think I have ever seen a mate quite like this, with a Queen and two knights giving a sort of epaulette mate.

White to play and mate