This is the episode where Lewis learns about conflict of interest and why suspects or friends of a victim should not take part in a police investigation.
One of the characters in this episode of Lewis was called Richard Helm, a name similar to that of an infamous CIA director. And so episode was about spies - or at least Stasi agents.
ITV1 started its run of the second series of Lewis with And the Moonbeams Kiss the Sea. The second series has four episodes, one more than the first series.