Concentric Square Tactics Drill

Some of you may be familiar with the Concentric Square drill from de la Maza. It's been referenced elsewhere in this forum as well. You are meant to move a black rook around a black king finding forks and skewering opportunities with your white queen.

If I'm doing this drill the way I think I'm supposed to. There is no forking or skewering opportunities until the rook travels along the concentric square to Rf3, at which point there are skewers at Qb7 & Qa8. In other words, it's impossible for the queen to take the rook without allowing the king to recapture the queen through the first 10 or so positions the rook is placed in on the concentric square. Is this correct? Or am I doing something wrong?