M1, T3: While Henry is interested in aging and how to die, New York's wealthy elderly are chasing a way to turn back the clock. A clinic is dispensing a pricey product called Aterna, which is supposed to provide the much-sought-after fountain of youth. Instead, Henry and Jo are confronted with multiple deaths from the costly potion, which, instead of revolutionizing the aging process, is turning people's brains into Swiss cheese. Henry remembers back to a dear friend who was diagnosed with tuberculosis in 1906 and discovers a link to this current case. Meanwhile, unbeknownst to Henry, Abe would love to be young and youthful again and is tempted to try Aterna. Plus, Henry learns that however long you live, you must live every day and hour like it's your last. Guest stars include Eric Morris (Blue Bloods) as Dr. James Carter and Mather Zickel (House of Lies, Newsreaders) as Dr. Frederick Gardner.