In our cover story, David Pogue looks at the hit online instruction series MasterClass. Plus: Singer Demi Lovato talks with Tracy Smith about her life since surviving a 2018 heroin overdose; Martha Teichner visits with abstract artist Frank Stella; Ali MacGraw and Ryan O'Neal reminisce about the making of the classic "Love Story" with Ben Mankiewicz; Seth Doane reviews an exhibition of Roman and Greek antiquities which have been out of public view for about 70 years; Rita Braver tells the story of a man, adopted at birth, who reconnects with his birth mother; Conor Knighton explores extinct species that may not be extinct; and Luke Burbank reports on the rise in sports betting, and tests his luck at a Las Vegas sportsbook.