Actually, it's escaping mate with mate.
1.Qb8 + would mate but ... 1. ... Rc8 mate.
Black mates in one regardless of white's move.
I was just messing around with the pieces when I saw this.
The original idea was without one of the (necessary) black rooks.
The problem with this one is ...
1.Kb7 ! Black still mates but it takes longer.
In the first diagram, with two rooks, 1.Kb7 is met by 1. ... Rc8 mate.
I may start posting some more serious stuff again real soon.