Does Isochron Scepter let you cast a copy of an imprinted instant for free?

Isochron Scepter has an activated ability with a cost of {2} and an effect that creates a copy of the imprinted instant card and may let you cast that copy without paying its mana cost. Per CR 702.58 (imprint) and the card's own oracle text, you exile an instant card with converted mana cost 2 or less when Scepter enters the battlefield, and then pay {2} each time you activate it.

When you activate the ability, you create a copy of the imprinted card (CR 707.10 covers copying objects). You may then cast that copy without paying its mana cost (CR 601.2b allows casting without paying mana cost when a spell or ability explicitly says so). Because the copy is cast this way, alternative or additional costs can still apply, but no mana is required for the spell's printed cost.

Importantly, the {2} you pay is the activation cost of the Scepter's ability itself — not the mana cost of the spell. The instant copy itself is cast for free. If you choose not to cast the copy, it simply ceases to exist (CR 707.10c, copies not on the stack cease to exist).

Example: You have Isochron Scepter with Lightning Helix (normally {R}{W}) imprinted. You pay {2} to activate the Scepter, create a copy of Lightning Helix, and cast it for free — dealing 3 damage and gaining 3 life without spending any red or white mana.

One condition: you must have actually imprinted a legal instant card (CMC 2 or less) when Scepter entered the battlefield. If no card is imprinted (e.g., it was exiled later with no card), the second ability produces no copy and cannot be meaningfully used.