They were on their way now to pick up a cold trail.

We have only sniffed out the first few steps on a long cold trail.

"Four weeks is still long enough to leave a cold trail."

It is difficult to pick up a cold trail, the police said.

But it will be a cruel, cold trail you take, my sister.

And she was left picking over a very cold trail.

It should be able to pick up a cold trail as well as a hot one.

With the trail already cold, search efforts had been abandoned as futile after a few days.

By then, Harald could be dead or, at very best, the trail too cold to follow.

With the trail at least two weeks cold to start?