The Guardians/Story Arcs

Series wide story arcs appear in the Doctor Who spin-off series The Guardians.

Rift arc
The entire series 1 is encompased by the Rift story arc.

The Breaking Dawn
The Controller just before his defeat warns Morbius that "the Rift will open and Darkness will fall".

The Space Gangster
After the team teleports back to The Protector, an orange curtain of energy(similar to the Cardif rift) can be seen in the backgound

Meta-Crissis
The Rutan prophecy: "We have seen it, the Darkness falling over creation. The Dark Lord shall open the Rift and the evil ones shall come, and onlly the Light Guardian can stop it".

Space Swap
The Bodyswaper says that he only swaped bodies with Morbius because "[he] saw the darkness and the end of everything".

The Degradation of Time
Commander Cr'it of The Skaro Degradations says that he escaped the Time War via a rift in time, later in the episode he atempts to open it and rescue the rest of the Degradations.

A Dark Collective
Another Rift similar to the ones in The Space Gangster and The Degradation of Time is discovered by the team and later used against the Darksmiths. This is the first time Morbius wonders what's causing the Rifts to occur.

Old Times in New York
Jack's former partner James Ducard atempts to tap into the power of a space-time rift found on Earth.

The Rift Opens
Warned by the Cloister Bell, the Guardians discover a colosal Rift in the Solar Sistem.