I'm trying out highly simplified hints. I stole the idea from Reddit chess bots. Let me know what you think.

Hint #1 (move)

Queen!

Hint #2 (move)

Qh4!

Hint #3

Black has mate in 4

Spoiler

The boards are interactive - chess.com | lichess.org

Qh4!

Black has mate in 4

Best continuation: ... Qh4 2. Rfb1 Qxh2+ 3. Kf1 Qh1+ 4. Ke2 Bf3#!