Cheapest priced copy (Throne of Eldraine): $0.35 at Card Kingdom, near mint, their price list as of .
Trapped in the Tower 
Enchantment — Aura · Common · Throne of Eldraine · #33
Enchant creature without flying
Enchanted creature can't attack or block, and its activated abilities can't be activated.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Throne of Eldraine | 33 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 4 October 2019Activated abilities contain a colon. They're generally written “[Cost]: [Effect].” Some keyword abilities are activated abilities and will have colons in their reminder text. Triggered abilities (starting with “when,” “whenever,” or “at”) are unaffected by Trapped in the Tower.
- 4 October 2019If the enchanted creature gains flying, Trapped in the Tower is put into your graveyard as a state-based action. The creature won't get stuck in the tower again when it loses flying.