How to mate after lesson 9,Champion Tactics with GM Wolff - Interference

beginner here,

doing lesson 9.  it says white has no defense after Q goes to c3 but if I play the computer, white Q goes to b1 and I can never get my pawn Queened.

can anyone show me the steps to get white mated?

for having "no defense" I am having trouble closing it out

Use Medium or higher on cpu level

one thing I didnt make clear, this is not part of the lesson but the lesson doesnt end with a mate, just a statement saying white will lose.  i tried to play that out but was not successful unless I have the pawn take the rook.  that seems strange since the lesson seemed to be about how to Q the pawn.

Rook to d8 would protect the pawn so when the pawn promotes, promote to either rook or

queen, then white rook takes, then black rook takes and forks king and queen leaving white with a forced mate.

then white goes to Re1 so you can't get a queen

Oh

" i tried to play that out but was not successful unless I have the pawn take the rook.  that seems strange since the lesson seemed to be about how to Q the pawn."

Taking the rook does promotes the pawn. The game is won, which is all that is necessary to demonstrate the concept.

i only can come up with queen to b2 if you ment black to move

I was assuming the diagram was really "Black to move," since White's queen has already moved to b1, as in the description.

i only see queen 2... qb2 3.qc1 re8 4.nd3 rd8 5re1 q xc1 6.rxc1 rxd3 7re1 rd1

but i suck at chess so probably im totally incorrect and made a million blunders, but i guess something in that direction should be correct.

ok actually im totally crazy ok the best i can come up with now. 1.. qb2

2.re1 qxb1 3.rxb1 re8 4.re1 rd8 and then the game is just totally winning.. i believe this time im correct, i have no clue how i got to qc1 for white.

yes, it should say Black to move.

This was my first post and I dont think I did the board right.  also, I think there is a way to post so you can play it out vs the cpu which would be nice.

@Jamie,  I guess that promotion was the point of the drill.  I was thinking that the new Queen would actually be in play for a little bit.  That does seem to be the only way to continue with an advantage for black.

Still, as I play it out.  I am not seeing the "no defense" situation that the lesson describes.  even after taking the rook, black only has a small advantage, or am I missing an easy forced mate?

@Tetsuo,  I think your solution works too. The promoted Queen wins the mate so that is a little more satisfying even if it is a little more complicated.

...Qxb4 seems strong. White has to avoid the Q exchange so minimally you would end up the exchange after ...exd1(Q)+.

Gerry

@gerry,  white has the advantage if the pawn doesnt get Queened.  White will put Re1 against most black moves.

@tetsuo, upon further review, I dont think your solution works.  after 4.re1 rd8

5 Nd3    and now Black has options. 

1...exd1=Q+ 2.Qxd1 Rc8 wins I think- the back rank mate/queen fork are unstoppable

1...exd1Q+ 2.Qxd1 Re8 3.Ne4 Qe5 and black is ahead by like 2.5 pawns. You can easily get to the endgame up an exchange and win it.

yes you are right i missed f3 and king f2

thinking about it im probably too crazy for chess