Try to solve this puzzle on your own, and then play through for the
answer --no peeking! :)

In only twenty-one moves, have the Rook visit every square once, and
only once, with the following conditions:
- the Rook must capture the Bishop on its 10th move
- the Rook must capture the Knight on its final move
- two consecutive moves cannot be made in the same direction
(The Rook's initial square is given as having been visited already)