You have an instant and/or sorcery card in hand with cycling.
Lands you control can tap to produce ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough additional mana to cycle the instant/sorcery card in hand.
Steps
Activate all mana-producing lands you control by tapping them, adding at least ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough mana to pay for the cycling cost of an instant/sorcery card in your hand.
Cast
Turnabout by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) , untapping all lands you control.
Activate any instant/sorcery card in your hand's cycling ability by paying its cycling cost and discarding it.
Escape Protocol triggers, causing you to pay ({1} magic symbol) to blink
Scholar of the Ages.
Scholar of the Ages enters the battlefield, returning
Turnabout and the card with cycling from your graveyard to your hand.
Resolve the cycling ability from step 2, causing you to draw a card.
Repeat.
Results
Infinite card draw.
Infinite draw triggers.
Infinite self-discard triggers.
Near-infinite ETB.
Near-infinite LTB.
Near-infinite magecraft triggers.
Near-infinite mana lands you control can produce.
Near-infinite storm count.
Return all instant and sorcery cards from your graveyard to your hand.