Mr Blue follows happily. 

Gwin follows on the safer path as well.

valkas also follows them, walking from behind the group 

You all backtrack a little, and go around the glass to where the knife lays on the ground. It's about half covered in dried blood, and the rest of the metal is almost completely oxidized, with a few patches of exposed metal. Dried and cracked blood has pooled around the knife, with a colony of mold forming at the edge.

Emelina points at the knife "Well here is the knife I saw through Melly"

valkas inspects the knife closely, and tries to inspect the blood to see if it was new or old
(investigation?)

(ooc: Yep, make that Investigation check!)

investigation: 1

( OH, ok then)

You take a good look at the knife, squinting to see if you can look at it better. Only one thought pops into your head at that time: That is definitely blood.

"well this is certainly blood. . . i wonder if someone had a fight trough here?"

Gwin carefuly walks around the broken glass, looking for footprints or traces of dried blood leading away from the knife.
Perception(?): 7

Mr Blue starts to realize the hopelessness of this effort and stops to perform a bit of magical tinkering.

He works quickly with some ephemeral substance that seems to appear out of nothing, and says "We can get through this, with hope." The knife will emit this message when someone gets within five feet of it, forever. 

"Good idea Mr. Blue now would everyone want to head back?" says Emelina as she gazes at her surroundings.

Gwin:

You watch as Mr. Blue works efficiently with the material, and apply it to the knife. You all take a step back and look at it, the message glowing on its hilt.

'That's a kind message, Mr. Blue,'  Ainsley says. 'Perhaps that will give other survivors the strength they need to go on.'

Before they leave, Ainsley looks around for signs of struggle around the knife.

Perception (?): 17

Ainsley:

valkas was feeling uneasy from the discovery. that means that there was probably some kind of dangerous person or beast close by. he tries to look around, trying to find any clues where the holder of the knife, or something else went to 

investigation: 2

Valkas:

"i see. . . whoever it was, i think they went with the street. there's blood over here. there's also blood going to the building on our left. . . but the bloody footsteps go alongside the street." he says, pointing at the blood, at what seemed like footsteps