The Medford Public Library is co-sponsoring an “Author Hour in Massachusetts,” an online program in which bestselling author Vicki Delany will discuss her new cozy mystery novel, “The Incident of the Book in the Nighttime: A Sherlock Holmes Bookshop Mystery.” Delany is one of Canada’s most prolific and varied crime writers, having published more than 40 books. Register through the library’s new online calendar to receive the Zoom link.