How defend this position?

Black to move,

Black is one piece up, but Qxf7 checkmate is threatened. Maybe I am missing something, but I do not see any other way to defend but 1...Nd7 2. Qxd7, followed by 2...Qc1+ and 3...Qf4+ . Then I go for perpetual moving the queen between c1 and f4.

Not sure how I came across this, but here is what I see.

Nd7, QxN Qc1+, Kh2 Qf4+, g3 (forced) QxB regaining material and defending f7.

If Nd7, QxN Qc1+, Kh2 Qf4+, Kg1 then Ra1 forces mate as the h2 square is covered by the queen, creating a mating net. No need for perpetual, black is won

Yes, you are totally right. I proposed exactly the same variation above, but forgot about ...Ra1+ at the end, so I though it was a draw. With ...Ra1+ it does look like a win for black.

But you both forgot about something. 1... Nd7 2. Qd6+ Kg8 (forced) 3. Rxd7 and all the fun ends here. White has recovered his piece and even protected himself from nasty checks. He will easily recover some missing pawns and the position might be a draw.