Spellbook of the Master

You have no maximum hand size
Whenever you cast an instant or sorcery spell, put
a page counter on Spellbook of the master, then
investigate. (Create a Clue token. It's an artifact with
"{2}, Sacrifice this artifact: Draw a card.")
{1}{u}, {t}: Remove 3 page counters from Spellbook
of the master, target instant or sorcery card in
your graveyard gains flashback until end of turn.
The flashback cost is equal to its mana cost.