As well as the self-referencing of the #4.11 title The 4-1-1 (2019), "4-1-1" is also slang for information or 'the lowdown' about a situation, derived from a Directory Assistance phone number in the USA & Canada.
Zelda and Kady believe that they are trapped in the Poison Room, unaware that Alice carelessly left the back door open when she 'imprisoned' Plover in there.
The nursery rhyme said by Fen and Tick go as follows:
"Thirsty Roderick, Thirteenth of his line, always liked to have a good time. He hides his drinks from his many daughters. Builds a cistern to hoard the waters. Underneath the castle fair. If you jump, you'll skip the bear!"
"Thirsty Roderick, Thirteenth of his line, always liked to have a good time. He hides his drinks from his many daughters. Builds a cistern to hoard the waters. Underneath the castle fair. If you jump, you'll skip the bear!"