The Crucible

"Use the two "Sockets of Power" to grant super enhancements to the towers you put in them. Pass 25 brutally tough rounds using all your skill and cunning."

- Official Description

 is a Special Mission for Bloons Tower Defense 5 Deluxe and special event for BTD5 Mobile/BTD5 Steam. It is played on the beginner map Bloonhenge. It is unlocked upon reaching Rank 32 on deluxe, rewarding 1000 upon completion, or some other things on steam.

In the mission, you must beat 25 special modified rounds on Medium Difficulty, using the two "Sockets of Power." Placing towers on them make them attack dramatically faster as well as having a slightly increased range and Camo detection.

On the 12th December 2018 update, The Crucible is added to BTD5 Mobile and BTD5 Steam as a special event. Players can play it once every 4 hours for special rewards that vary each time. 

Trivia

 * A crucible is a metal or ceramic container used for smelting metals. It can also be used to describe an intense situation or trial.
 * The music in this mission is different than playing the track normally.
 * The game does not allow the player to place two towers on one socket of power, despite there being enough room for it.
 * But, if players use a Monkey Engineer with the sentry upgrade, it can spawn on the pillar with it if there is a tiny bit of room for it.
 * The sockets of power don't affect Special Agents, Banana Farms, or Monkey Villages.
 * Monkey Villages cannot be placed on the sockets of power due to them being too big to fit. Banana Farms can, but it does nothing to the Farm itself.
 * Regen Farming is possible on this special mission.
 * Placing a Tower in the Crucible with Overclock, M.I.B Call To Arms, Jungle Drums and T2 Specialties can make a Tower attack 5x faster, such that a 1/x Ninja Monkey attack nearly as fast as a Super Monkey.
 * If you put a 4-2 Spike Factory in one of the sockets, it appears that the hatch isn't moving, because of the hypersonic speed it is producing Spiked Mines at.
 * This is only true on Fast Forward, though it still opens and closes very fast.
 * Portable Lakes don't fit on the sockets.
 * Because of this, it's impossible to place Monkey Buccaneers and Monkey Subs on the sockets of power.
 * A maxed TOTMG/TOTVM on the Socket combined with a 2/4 Village and multiple Overclocks is the strongest a tower can get in BTD5.
 * Despite the mission appearing in BTD5 Mobile/Steam, the track it is based on does not appear in those versions.