For others, it can exercise the same attraction as any complex intellectual puzzle.

Magic was like a huge and complex puzzle to him.

But in other ways, the man was a complex puzzle.

At times this can be difficult with complex puzzles and a lot of backtracking required.

His lips moved silently, as though he was working through some complex puzzle.

Once again he felt the pieces of some complex puzzle whirling in his brain, but they still didn't fit together.

Once again, he felt the pieces of a complex puzzle whirling around in his brain.

He has continued to produce complex puzzles, some of which can be used to teach basic geometry.

Trying to get inside her head was a big adventure, a complex Chinese puzzle that occupied my mind and time.

It's also a fiendishly complex political puzzle, and there may not be much time to decide how to act.