An unexpected development

You follow behind the two adventurers, unseen by either of them as you flit from shadow to shadow but observing them intently, looking for an opportunity to present itself. All of a sudden there is a soft click, and a twang, and the thief lets out a yelp of alarm!

What the hell?! There aren't supposed to be any traps here!

She shouts, while motioning to the nervous wizard to keep still. You can't help but agree, there aren't supposed to be any traps here, just you and your fellow wraiths. You drift closer, cautiously...

Sonofabitch! What kind of ass leaves one of the these around here, of all places?!

The thief's exclamation makes you briefly think you've been spotted, and you prepare to flee, but then you notice the small dart she holds in her hand, it's tip green with some noxious poison. A poison you recognise. Some adventurer classes hunt you and your kin for the main ingredient of that poison - it takes hundreds of dead wraiths to make even one dose, but the resulting poison inflicts a severe amount of STR damage on anything wounded by it. Some adventurer must have left this trap behind as a prank, and the thief unwittingly triggered it!

You don't hesitate, this is the best opportunity you could ever get, and dive towards the cursing halfling, your ethereal talons raking through her as you hope beyond hope that the poison did enough STR damage for your Withering Grasp to prove fatal. A dagger glides harmlessly through your body as she tries in vain to defend herself, the mage flings spells your way but they are equally ineffective, her level too low to cast anything capable of hurting you. With each strike of your claws the thief's arms tremble with weakness...