Hotel Babylon is closing. Tony desperately pitches the hotel to an Asian businessman, but the deal goes into freefall when Tony refuses to meet his demands. Meanwhile, a terror alert throws Central London into chaos, and a crowd seek refuge in the hotel. The team pull together fantastically, and a millionaire caught up in the bedlam is so impressed that he decides to buy Babylon, securing its future. Elsewhere, Anna is nearly eight months pregnant, but is in total denial.

A couple who are both celebrities hold their joint 40th birthday party at the hotel. Anna finds out that they are not as happy as they seem together. Sam ignores Juliet's advise and better judgment when he lets lets two rival boxers stay at the hotel.

The staff take part in a treasure hunt around the hotel searching for valuable emeralds claimed to be hidden there. Gino finds himself being conned by a man staying at the hotel. Tony discovers that a former film star staying at the hotel isn't quite as she seems.

Sam and Juliet's love grows, but a hidden secret threatens their relationship. Tony hosts a party for other concierges while Gino tries to find the identity of the writer of an erotic novel among the staff. Also, Mel's lie starts to crumble.