Drayton, a perfectly normal and respectable businessman, is sacked from his job as general Manager of the Dynaflow company after only four weeks in office. The company has been bought out by a Mr. Purvis and the price is suspiciously low. Drayton contacts the I.B. and it doesn't take Smith long to realise that a colossal Purchase Tax swindle is in the making. The trouble is, how to prove it. And that's where Smith has to start playing the waiting game.

The Customs men at a Continental car ferry become suspicious when a man makes too many trips through their port.

Sir John Dolan and Stuart Campbell are close friends. And we all need friends, don't we?

Ross McInnes learns that a good I.B. man must think of the Department above all things - even above friendship.

When Penman's flat is broken into by a young man, a chain of strange events leads the I.B. into a macabre and dangerous case.

Smith arrests two old clients and oversteps the mark. The two he has accused insist that he himself should be investigated.

Fortunes can be made from a leak of information from a Customs office. Smith and McInnes attack the problem from two sides, both with equal application.

Perhaps to be a good I.B. officer one should have no emotions at all. Ross McInnes finds this out the hard way.

When Paul Valery, an international con-man, has a mysterious visitor, the I.B. become involved with a very undesirable alien.

When Paul Hasek, a foreign diplomat, is caught in a compromising situation, his privileged position is used as a cover for smuggling.

Any way of reducing the price of mink coats would be welcomed by some women, even if it means depriving the country of revenue.

When a man collapses in a Customs hall he is found to be carrying a large quantity of gold.

Smith is involved in butter smuggling between Northern and Southern Ireland and he and McInnes find themselves up against a very professional operator.