As another Twitter user pointed out, we were given a "considerably kinder ending" than the one John le Carré gave in the original novel. While the majority of the series stayed pretty close to the book's narrative, there were a few key differences in the final episode. For one, the briefcase bomb that Charlie delivered actually happened in Munich, not London. In fact, Charlie doesn't return to London until long after everything has settled down and she's deemed well enough to go home. In le Carré's writing, Charlie struggles far more with the after-effects of what happened than we see on screen and her reunion with Becker, who also went through great emotional turmoil (which we don't see either), happens at one of her plays when she returns to her lousy acting career.