煤气

煤 = 某 + 火 : Mahatma Gandhi (m) is looking for some food in the Eiffel Tower's kitchen (ei2) when a fire (火) breaks out at the coal (煤) store and blocks the way down. To stay calm Mahatma Gandhi grabs a ukulele and plays "somewhere over the rainbow" (某).

Mnemonic symbol: a balloon. The Queen of Hearts is disappointed by her balloons. She expected them to float upwards, but in the space station's bathroom, They float randomly in all directions.