So you have to do some detective work to figure out what's really going on.

I'd done more than enough detective work for one day.

I'd like you to do a bit of detective work for me.

Then we went up to my office to do some serious detective work.

And a bit of good detective work on your part, too.

I'd just like to say in the first place that I think you did good detective work.

We'll have to do a little detective work on it.

"But first I'm going to take time out to do a little detective work."

Sometimes it's a matter of doing a little detective work.

All those months of detective work and he had nothing to show for it.