The entire saga is devoted to the Others - humans able to draw on the magical force flowing through the world.
Each Other must either choose Light or Dark - usually they make their choice the first time they enter the Twilight and neither Watch may influence their decision.
The decision, once made, is final except in cases where an Other does an act of enormous light or dark, such as Merlin, or Arina.
Vampires and werewolves, lowest form of Others, are always Dark and they are the only kind of Others who are able to pass their abilities to ordinary humans - otherwise an Other cannot be made, only born.
This is of course, excluding the use of the Fuaran, a powerful magical book, which when used, may turn any number of ordinary humans into potential Others.
Dark Others occasionally choose to remove the cause of the pain or fear from the humans mind (see twilight watch).
Except for the prologues, the events of each story are written in a first person narrative using the voice of the Higher Magician character Anton Gorodetsky, a member of the Night Watch.
Events in each of the prologues are written in a third person narrative and take place entirely outside of Gordetsky's presence.
Anton Gorodetsky is learning to use his new power when Gesar sends him to assist the Scottish Night Watch in Edinburgh in a murder investigation.
After the Night Watch is attacked by ordinary humans equipped with magical amulets and bullets, Thomas and Anton follow someone to the Twilight.
When Anton is visiting the Night Watch in Uzbekistan, they are once again attacked by humans with amulets and magical weapons.
They are attacked again and Anton learns that his one-time friend, the Inquisitor Edgar, is one of the mysterious trio of Others.
Back in Moscow, Anton figures out who is the Dark Other in the mysterious trio - it is Gennady Saushkin, Kostya's father.
Edgar and Gennady kidnap Anton (they can't get to Nadya) and take him to Edinburgh, so that he can help them figure out a way to get to the Crown.
They tell Anton that Nadya is dead due to them planting a nuclear explosive near his apartment building.
They meet the third part of the trio, or as they call themselves, the Final Watch - the witch Arina, who managed to change her affiliation to Light.
However, the lost Others asked Anton to forgive, so he allows Gennady and Edgar to die, so that they can join their loved ones before it is too late.
Then Anton activates the Crown, and all Others in the Twilight die, including the incapitated Dark Others in the Plain of Demons.