Assassin's Arcana

A orb of green energy forms floating in your hand and is thrown to a point you choose within range, then turns into an explosion of vaporized poison. Each creature in a 5-foot-radius sphere centered on that point must make a constitution saving throw. A target is affected by the effects of the poison that was consumed by the spell as a component of casting the spell on a failed save. Creatures that are surprised that would make this constitution saving throw, has disadvantage on it.

The poison spreads around corners.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the area of effect increases by 5-feet for each slot level above 1st.