This was spoiled by ignoring the end of Season 4 where Luther promised to go after the woman who killed Alice. Apparently we are meant to forget that, also the fact that Luther and Alice were in love and planning to go away together. There are a lot of holes in this series - how they managed to get into the loft without a ladder in about 30 seconds flat - how they don't bother checking ballistics before accusing people of shooting someone - why the men employed by Cornelius would not check a random woman turning up at the door just after his son had been returned from being kidnapped - how Luther would tell Alice he had killed Cornelius when all she had to do was dial his number - why Alice would shoot the oh so clever Ds who practically solved the case all by herself - why Alice would mess around and not just shoot Luther and depart - why a hitman would kill a policeman without being ordered to or paid to thus bringing the whole might of the police force down on Cornelius - why Alice would shoot from outside the house with not much chance of killing Cornelius - she isn't usually so impractical. How strange that when Luther went into the house where the killer was it was night time and when he came out it was broad daylight. Note to film makers - audiences do have brains and often use them to your detriment.