There's not much in the way of nightlife in Blois, but you could saunter down to Le Velvet Jazz Lounge, 15 bis rue Haute (tel. 02-54-78-36-32), off rue Denis Papin. This is part of a 13th-century abbey but is now a venue for weekly jazz concerts. Otherwise, this is a classy joint for a drink. From Tuesday to Sunday it becomes a salon de thé from 3 to 7pm, becoming a bar after that (usually open until 2am).
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.