After years of chilly relations with the Vishwani government, the Foreign Office (and MI5) are invited to the embassy for a formal evening, now that the government has changed hands (MI5 has been asked ""in the new spirit of openness"" to bug the embassy). Unfortunately, terrorists have other plans and besiege the embassy - with agents and their wives still inside. The wives, of course, have all been told something different about where their husbands actually work. Amidst this backdrop, Peter and Dexter must save the day without getting anyone hurt in the process.
After Dexter bungles a safe-cracking operation, MI5 and MI6 make a wager. MI5 must break into MI6's offices, open a safe on a specified floor in a specified room, and bring the contents to MI6. Drummond realizes they must hire a professional for this job - after all, he won't be losing the bet to his friend at MI6 - so he arranges for the release of a thief from prison, and Peter gets to babysit this man of dubious fashion sense and even more dubious principles while the ""caper"" is afoot. But is the bet on the level or is Drummond being manipulated?
MI5 gets wind of a novel about to be published called ""The Coldest of Wars"" that's going to ""blow the lid off MI5"". When Peter reveals that his wife Sarah, who works for a publisher, has just been reading a manuscript by the same name, he and Dexter are ordered to intercept the manuscript before it is published.