I don't understand why I lost Infinitize the Maxitude?

Multiplayer Discussion
1

So I was playing this weeks Raven brawl and I got Infinitize the Maxitude

after I played it I did NOT get it back in my hand at the end of the turn and I don’t understand why ???

2

It returns to the hand at the end of the turn if the Finale keyword is used.

Finale means that this card must consume all the mana that you have left. So in this case you have to use the card while you have 2 mana left.

Legendary · Spell · Festival of Legends · Discover a spell. Reduce its Cost by (1). Finale: Return this to your hand at end of turn.