The footage is shaky and erratic, the terrified teenager capturing it on her camera phone doesn't want to look too obvious.
There are shots of the gravel path ahead of her – and then the field of view tilts upwards to reveal her friend, Abigail, who's walking a little way behind her on the old railway bridge, stepping carefully but as swiftly as she can over the wooden sleepers.
The reason that Libby German started filming suddenly appears in shot: the man who is following behind Abigail.
He is muffled up heavily against the chill of the misty, grey February day. He too is trying to look nonchalant, head down and hands in pockets, but it is clear the girls are his focus - and he's gaining ground on them.
Libby, 14, and Abigail Williams, 13, can be heard exchanging nervous whispers on the video.
