EXIT BERLIN, by Tim Sebastian (Bantam, $76). THEY were euphoric days, particularly for the democracy-espousing West. The communist regimes across Europe were falling like nine pins, along with that most graphic symbol of the totalitarian state, the Berlin Wall. Off to the side, a small group was holding a wake for the end of the Cold War - these were the spy novelists. But one of the form's brightest lights, BBC correspondent Tim Sebastian, went behind the headlines for this stark tale, set during and immediately after the Berlin Wall was breached. This was a time when enemies became allies and allies were banished to the other side of the fence, not the best place for James Martin, a British agent in East Germany working for the feared Stasi in the guise of a defector. Sebastian forgoes the simultaneous episodes around-the-world style of John Le Carre and Tom Clancy for a work driven by Martin's thought processes as he works through the intrigue and betrayal he has suffered. As the wall tumbles around the Stasi, Martin initiates a mad scramble to discover the traitor passing information, which resulted in the demise of the British agents in East Germany about five years earlier. It is not a move either sanctioned or welcomed by his bosses in England or East Germany. The action moves from drab East Berlin to grey England to sunny Washington, only to return to Berlin, never escaping the shadow cast by the Stasi or its one-time ally, soon to be enemy, the KGB. All the while people are dying violently, although Sebastian never allows the deaths to overpower the plot, carefully moving it ahead and replacing one evil presence with another, or one suspect by pointing in the direction of another. In the shadowy world of espionage few of the characters are clearly delineated by their ideologies - the British spy chiefs being as devious at manipulating people as their enemies, only perhaps a little more subtle. The lines blur further with the deals being made by the Stasi members who have backed a failed regime. The chase to the denouement gathers speed with Martin being pushed and pulled by events inspired by him but out of his control. The spare style of writing is aided by Sebastian's use of Martin's observation of the Englishness of his outlook, and how his opponents look at similar things. There is a love interest which also serves to introduce the American angle on a truly international event. This dimension occupies a good deal of Martin's thoughts as they relate to the unravelling of the plot and relationship with the woman, Cassie. Sebastian skilfully introduces and establishes his cast without losing sight of the plot, no mean feat in such a complex story. He also casts a new light on the collapse of East Germany and its meaning to the various players on the world stage. An intelligently written book which proves the spy novel is not dead.