WHEN someone comes through your side garden gate with a briefcase, looks in your conservatory window, claiming to know you and wanting to talk, of course you are going to think he's selling something you don't want!

Well, you do live the high life in a beautiful Georgian house in the Home Counties. Who needs him?

But when he returns and you haven't noticed him locking your garden gate, what is coming?

The compulsive psychological thriller, Dangerous Obsession, on at the Apollo Theatre this week, that's what!

John arrives with memories of a dinner party and you dancing with him. He's claiming he has business to discuss with your husband.

You begin to remember talking to him and his wife at that party. You invite him in. You offer him a drink. You don't notice when he locks the conservatory door and pockets the key. What does this man actually want?

For John, superbly played by Jason Harris, it's searching for truth, inch by inch, by whatever means.

For Sally, brilliantly acted by Holly Squires, who drank a bit too much at that party, and is doing so again now, it is finding out the truth.

And when her husband Mark, cleverly played by Scott Walsh, comes in, will he want to surrender it?

It is said people can cope with deceit. It's truth they find difficult to handle.

This play, written by N. C. Crisp, British TV writer, dramatist and novelist, and a master of suspense, has the wall of the 1980s around it.

There's no internet. No mobile phone. Lock the doors, disconnect the telephone. No contact. No escape.

Splendidly directed by Glenys Lloyd Williams, this play is too good to miss!

Is it friendship John wants? Is it sympathy? Maybe it's money. Is it sex? Is it revenge? See how little bits of evidence filter out. What exactly has led to this moment? And wait for what happens!

Catch Dangerous Obsession at the theatre daily until Saturday, with the exception of tonight (Monday).