It takes Stocke a while to notice, in truth. Though he doesn't always take souls, especially when dealing with monsters, there's very little else humans can offer him - his business is thorough, vicious, arguably quality work (if that's the kind of thing you want to praise...) but doesn't often lead to repeat customers. And he has slow and fast periods as anyone else does.

Breaking an arranged deal off is another thing altogether. To do it Amelia would've had to interrupt a human already on the way, and Stocke in a slow time of business grows quickly curious about any delays.

Which means the shade's just in time to overhear Amelia bargaining.

For a moment Stocke's frozen in place; if he expected to ever hear from the harpy again, it wasn't something like this. His impression of Amelia was of someone far more likely to be direct in her anger. But then - then he's furious in return.

He can respect someone's urge to balance out a grudge, shade or not. But here's the second thing about vengeance, the reason he gets people selling to him: you have to be strong enough to carry the retribution out and get away with it. The shade's confident (cocky) enough to believe that Amelia isn't.

There's a rattling static snarl from the dark of the street. It's the only warning Amelia will get before she's interrupted mid-sentence by a roiling shadowy mass - a shade on the warpath shifts new limb after new limb as fast as a panicked heartbeat.