He'd been there with me before, on cases without a single clue.

Finch is not going to leave us with a single clue.

Douglas didn't have a single clue what to say for the best.

And here is a single clue to those long gone days!

There is still not a single clue as to where it has gone - or why.

Thinking back on it, John could see now that she hadn't left a single clue.

Otherwise, they still had not a single clue about anything.

Even if the planet offered but a single clue he had to find it.

No more, perhaps, than a single clue, but at least a starting point.

"I tried hard to be a detective but haven't come up with a single clue."