Thousand-Year Storm | Spelljack

Cards

({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough mana to cast the additional instant card available.

Cast any other instant card from your hand by paying its mana cost.
Holding priority, cast
Spelljack by paying ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) targeting the instant.
Thousand-Year Storm triggers, creating at least one copy of
Spelljack that is targeting the original
Spelljack.
Resolve the first copy of
Spelljack, countering the original
Spelljack and exiling it with the ability to cast it for free from exile.
All remaining copies of
Spelljack fail to resolve due to having no legal targets.
Cast
Spelljack from exile without paying its mana cost, targeting the instant cast in Step 1.
Repeat from step 3.