Title: The Flash (season 4)
Content:  The season began airing on October 10, 2017, on The CW in the United States, and on CTV in Canada. The season concluded on May 22, 2018. Sky One acquired the rights to air the season in the UK & Ireland, airing it alongside the other Arrowverse shows. The season premiered October 17.
Title: The Flash (season 4)
Content:  Filming for the season began on July 4, 2017, in Vancouver, British Columbia, and concluded on April 21, 2018. Kevin Smith returned to direct an episode in January 2018.
Title: The Flash (season 4)
Content:  The fourth season of the American television series The Flash, which is based on the DC Comics character Barry Allen / Flash, premiered on The CW on October 10, 2017, and ran for 23 episodes until May 22, 2018. The season follows a crime scene investigator with superhuman speed who fights criminals, including others who have also gained superhuman abilities. It is set in the Arrowverse, sharing continuity with the other television series of the universe, and is a spin-off of Arrow. The season is produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Andrew Kreisberg and Todd Helbing serving as showrunners. The season was ordered in January 2017, and filming began that July. Grant Gustin stars as Barry, with principal cast members Candice Patton, Danielle Panabaker, Carlos Valdes, Keiynan Lonsdale, Tom Cavanagh, and Jesse L. Martin also returning from previous seasons, and are joined by Neil Sandilands. The series was renewed for a fifth season on April 2, 2018.
Title: The Flash (season 4)
Content:  Felton, who joined the cast as Julian Albert in the third season, would not be a series regular in the fourth season, and that there were no plans for him to appear. Julian's absence will be addressed "pretty quickly — there's a reason why he's no longer with the team," said Helbing. In the season premiere, it is revealed that Julian has returned to London. Kreisberg also confirmed that he had put on hold the planned return of Violett Beane as Jesse Quick due to the high number of speedsters on the show, but did not rule out a possible return in the future. Beane eventually appeared as Jesse on the episode "Luck Be 
Title: The Flash (season 4)
Content:  In July 2017, cast from the series appeared at San Diego Comic-Con International to promote the season, where exclusive footage was shown. During the panel, a trailer for the season was shown, with James Whitbrook at io9 feeling that despite the "grim" tone, there was "some fun signs of the team coming together to protect the city without [Barry],... Sprinkle in a few wacky things, like, say a goddamn Samuroid ripped straight from the comics, and ladies and gents, you've got a good season of The Flash lined up." Ben Pearson with /Film felt seeing Iris West deal with the absence of Barry was "a nice change of pace for that character", but anticipated that "Barry [would] be back two or three episodes in at the latest." Collider's Allison Keene also noted Iris "getting an actual storyline" with Barry gone, and similarly presumed that he "[would] be back in the fold by the end of the first episode" alike to Flashpoint in the third season. She added, "There are some new foes, lots of action, plenty of tech — it's great!"
Title: The Flash (season 4)
Content: Danielle Nicolet as Cecile Horton ; Kim Engelbrecht as Marlize DeVoe ; Mark Sweatman as Matthew Norvok ; Jessica Camacho as Cynthia / Gypsy ; Patrick Sabongui as David Singh ; Donna Pescow as Sharon Finkel ; Richard Brooks as Gregory Wolfe ; Hartley Sawyer as Ralph Dibny / Elongated Man and Clifford DeVoe / Thinker ; Katee Sackhoff as Amunet Black ; Jessica Parker Kennedy as Nora West-Allen 
Title: A Flash of Light (Homeland)
Content:  "A Flash of Light" is the fourth episode of the sixth season of the American television drama series Homeland, and the 64th episode overall. It premiered on Showtime on February 12, 2017.
Title: The Flash (season 4)
Content:  • Britne Oldford as Shawna Baez / Peek-a-Boo • Dominic Burgess as Ramsey Deacon / Kilg%re • Sugar Lyn Beard as Rebecca Sharpe / Hazard and Clifford DeVoe / Thinker • Chelsea Kurtz as Mina Chaytan / Black Bison • Violett Beane as Jesse Chambers Wells / Jesse Quick • Danny Trejo as Josh / Breacher • Vito D'Ambrosio as Anthony Bellows • Emily Bett Rickards as Felicity Smoak • Riley Jade Berglund as Joanie • Matt Afonso as Weeper • Stephen Amell as Oliver Queen / Green Arrow and Dark Arrow • Victor Garber as Martin Stein / Firestorm • Caity Lotz as Sara Lance / White Canary • Chyler 
Title: The Flash (season 4)
Content:  The season was made available for streaming on Netflix in late May 2018, soon after the season finale aired. It was released on Blu-ray on August 28, 2018.
Title: The Flash (season 4)
Content:  Goldberg as Dave Ratchet / Big Sir • Derek Mears as Sylbert Rundine / Dwarfstar • Paul McGillion as Earl Cox • Miranda MacDougall as Izzy Bowin / Fiddler  and Clifford DeVoe / Thinker • John Wesley Shipp as Jay Garrick / The Flash • Leonardo Nam as Matthew Kim / Melting Point • Max Adler as Jaco Birch / Hotness • Bethany Brown as Janet Petty / Null • Arturo Del Puerto as Edwin Gauss / Folded Man and Clifford DeVoe / Thinker • Katie Cassidy as Laurel Lance / Siren-X • David Ramsey as John Diggle and Clifford DeVoe / Thinker • Victoria Askounis as young Caitlin Snow

Question: when does flash come back on season 4 episode 17?
Answer: May 1, 2018.
April 10, 2018.