The first two seasons are enthralling. There are several moments a little over the top, but those moments provide entertainment value and you don't have to suspend your disbelief too much. The show does a great job of balancing thriller with levity and humor. It looks like they tried to downsize in season 3 and keep the scope small with a couple of interesting new characters. The plot was predictable, but the returning characters (especially Gary oldman) make it tolerable and worth watching. My biggest hang up about this season, particularly the season finale, was the countless number of cliche moments during action sequences. Several guns misfiring at the worst moment....bad guys pausing to say an eye-rolling line only to be attacked from behind, elite MI5 agents unable to shoot targets directly in front of them with thousands of rounds of ammo, two characters coincidentally running out of ammo at the same time so they have to get into a fist fight..... I get it's television and it should be entertaining, but this is supposed to be a spy thriller grounded in reality. Some of these redundant errors were too frequent to overlook and I started to feel like I was watching an 80s action movie. I felt like the writers just got lazy this season. I hope season 4 picks up The preview at the end of season 3 looks much more promising.