When it comes to Cisco and Gypsy, true love overcomes interdimensional barriers -- but can it survive a family visit from Earth-19? If The Flash star Carlos Valdes is to be believed, Season 4 will answer that very question. At Comic-Con International in San Diego, Valdes teased his character's "real love" for Gypsy and that the upcoming season will test the mettle of their relationship.

Asked about Gypsy, Valdes said, "All I can tease about it is that Cisco and Gypsy, they have their relationship and they're really taking it to the next level. There's a real love there between the two of them. However, some characters come about that really test that relationship."

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Here, Valdes is likely referring to the arrival of Gypsy's father Breacher, an interdimensional bounty hunter from Earth-19. During the show's panel at SDCC, Danny Trejo was announced to play the character, who will make his debut in this fall's Season 4. This likely spells trouble for Cisco, but Valdes seems pretty excited at the prospect of working with the Machete star: "Yes, I'm very much looking forward to working with this actor. Yes."

Starring Grant Gustin as the Scarlet Speedster, The Flash returns Tuesday, October 10 at 8 p.m. ET/PT on The CW. The series also stars Jesse L. Martin, Tom Cavanagh, Carlos Valdes, Candice Patton, Danielle Panabaker, Keiynan Lonsdale and more.