When Britney Spears checked into the Rosarito Beach Hotel in Baja California, Mexico, around 2:30 p.m. on Jan. 9 — just six days after the bizarre meltdown that ended with her being strapped to a stretcher and taken to LA’s Cedars-Sinai Medical Center — she appeared calm and subdued. But her behavior was still alarmingly strange.

“One of our waitresses spotted Britney alone in the hotel bar, singing to herself,” says Gustavo Lopes, the hotel’s reception manager. “She heard Britney mumbling the words to her song ‘Toxic’ in a very low voice. I don’t think Britney knew where she was, and my waitress thought she looked crazy.”

Read more about the many faces of Britney in the new issue of Life & Style—on newsstands now!