Hermione shivered as they passed the Dementors, while Ron gulped. Mayumi on the other hand, just kept stuffing her mouth full with chocolate.
"Oh," she suddenly perks up, "Right- later if Harry tells you that Snape bought Lupin something to drink and Lupin still drank it, it's not poisoned."
They shared a glance, and despite their suspicions, did not question it.