Basically, we have a haste scroll, 2 warlocks, a druid, a cleric, and me, an arcane trickster.
To use the spell scroll it must be on your spell list. The arcane trickster gets his spells from the wizard spell list. Nobody else has haste on their spell list and I can't cast 3rd level spells... YET, and potentially I can choose haste as a spell at a higher level.
Does this count as being part of my spell list for the purpose of attempting to use the spell scroll by making an ability check with my spell casting ability, as per the rules of casting a spell from a spell scroll that is on your spell list but is of a higher level than you can cast?