The Hands on the Clock Keep Ticking by violetmessages (gwen&ianto, JackIanto, GwenRhys | complete | 10235 | M)
They all knew it could happen to anyone. They’d all seen the proof. Even if it happened to a miniscule amount of the population, it was still a possibility.
But they had grown complacent. They had forgotten that they too were also at the mercy of the Rift, that the Rift did not make an exception for those who knew its existence.
They had forgotten until they were faced with it themselves.
In which Gwen and Ianto get sent back to 1969 by the Rift.