GW2DB

Can be bought at »Historian Cerin«, Blazeridge-Steppes, at the small house right of »Refuge Sanctum Waypoint«.

NPC stands next to »Priory Scribe Laeg«, but disappears from time to time in his house. Don't know what causes him to come out again.

where do i buy this?

Gives you a one time use Fire Storm spell.