Thrumming Stone and Swarm Intelligence on the battlefield.
({2} magic symbol) ({W} magic symbol) available.
Steps
Cast any other spell, or wait for an opponent to cast one.
Cast Lapse of Certainty by paying ({2} magic symbol) ({W} magic symbol) , targeting that spell.
Swarm Intelligence and Thrumming Stone trigger.
Resolve the Swarm Intelligence trigger, creating a copy of Lapse of Certainty, targeting the original Lapse of Certainty.
Resolve the copy of Lapse of Certainty, countering the original Lapse of Certainty and putting it on top of your library.
Resolve the Thrumming Stone trigger from step 3, revealing the top four cards of your library and casting Lapse of Certainty without paying its mana cost.