The Amazing Spider-Man, Vol. 2 #40/481

Approached by one of his students, Peter learns that a lot of street kids are vanishing... and nobody's looking for them. Convinced that they aren't just drifting, he begins to look into the problem. It's not long before he runs into the ghostly 'Shade'. Thinking his encounter isn't likely to just be a coincidence, he starts investigating this new player.