Thrumming Stone and Thousand-Year Storm on the battlefield.
You have cast at least one instant and/or sorcery this turn.
({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.
Thousand-Year Storm and Thrumming Stone trigger.
Resolve the Thousand-Year Storm trigger, creating at least one copy of Lapse of Certainty, with each copy targeting the original Lapse of Certainty.
Resolve the first copy of Lapse of Certainty, countering the original Lapse of Certainty and putting it on top of your library.
All remaining Lapse of Certainty copies fizzle due to no longer having a legal target.
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.