THE KNICK: Dr. Thackery (Clive Owen) performs reconstructive surgery on a former flame. (Mary Cybulski/Cinemax)

Patricia Clarkson hosts “PBS Previews: The Roosevelts” (WETA at 8:30 p.m.), a sneak peek at the Ken Burns’s seven-part documentary about Theodore, Franklin and Eleanor that will premiere on local PBS stations in September. Also included in this one-hour special: A tour through the family’s grand estates and the studio where Burns recorded actors reading their diaries and letters.

“Monumental Mysteries” (Travel Channel at 9) explores the stories behind a majestic North Carolina oak tree’s connection to witchcraft, a Boston home that was elemental in a slave escape route and how the Holmdel Horn Antenna changed the way people understand life.

RETURNING SHOW: “Bering Sea Gold” (Discovery at 9) returns for Season 4 with a dangerous diving excursion under the ice in the Bering Sea that puts one miner in serious danger.

Two back-to-back installments of “Four Weddings” (TLC at 9 and 10) have both a wedding at a drive-in theater and a wedding that uses carnival dancers as decoration.

Dr. Thackery performs reconstructive surgery on a former flame, and Algernon faces a challenging medical conundrum on “The Knick” (Cinemax at 10).

RETURNING SHOW: “Airplane Repo” (Discovery at 10) returns for Season 2 with Ken Cage and Danny Thompson in the skies to repossess luxury items from wealthy individuals who are behind on their payments.

Catholic education inspectors visit Lazarus House, which leads to the crew ending up in juvenile detention on “Jonah from Tonga” (HBO at 10).

SERIES PREMIERE: “BoJack Horseman” (Netflix) is the streaming network’s first foray into original animation for adults, with Will Arnett voicing a washed-up 1990s sitcom star — who just happens to be a horse — looking for a comeback. Aaron Paul voices his best friend, and Amy Sedaris is the voice of his agent.

Actors Ethan Hawke and Amy Sedaris come to “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), with music from the Secret Sisters.

Actress Julia Louis-Dreyfus and comedian Michael Somerville stop by the “Late Show With David Letterman” (CBS at 11:35), along with musical guest David Gray.

Entrepreneur Kim Kardashian is on this repeat “Jimmy Kimmel Live” (ABC at 11:35), with actors Damon Wayans Jr. and Jake Johnson. Plus, a performance from Disclosure featuring Sam Smith.

Rachel Lubitz