碼線

码 = 石 + 马 : Just when Mahatma Gandhi (m) and the unicorn (马) entered the ashram (a3) a giant rock (石) fell down and trapped them inside. There is an inscription written on it: if they ever want to leave, they will have to find the secret number (码) and say it out loud. There is also a hint: "how many roads must a man walk down?"

线 = 戋 + 纟 : Mnemonic symbol: barbed wire.

线 = 戋 + 纟 : The silk worm wants to use the floating tank in the anthill's bathroom, but there's already Marie Curie inside—and she secured the tank by setting up barbed wire all around it.