'Supergirl' season 3 premiere spoilers: Alex tells Maggie a secret

"Supergirl," starring Chyler Leigh as Alex Danvers, Melissa Benoist as Kara Danvers / Supergirl, Floriana Lima as Maggie Sawyer, Mehcad Brooks as James Olsen / Guardian and David Harewood as J'onn J'onzz / Hank Henshaw, will be featured in the new episode of the show titled "Girl of Steel," which will air in the US on Oct. 9. It will show Alex confiding in Maggie before they get married. Plus, Supergirl deals with the loss of Mon-El (Chris Wood).

Spoiler alert: This article contains more 'Supergirl' spoilers. Read on if you want to know about what will happen in 'Girl of Steel.'

According to a press release from The CW, the "Supergirl" season 3 premiere will feature Kara trying to deal with the loss of Mon-El. Meanwhile, Alex and Maggie are busy preparing for their wedding. However, Alex will tell Maggie a secret about their upcoming nuptials. As for Lena (Katie McGrath), she'll make a bold move. Plus, Kara will have a mysterious connection with a National City citizen. Jesse Warn directed this episode. Its teleplay was written by Caitlin Parrish and Robert Rovner while its story was written by Andrew Kreisberg.

'Girl of Steel' guest stars

According to the Internet Movie Database (IMDb), the guest stars that will appear in this episode are Odette Annable as Reign, Erica Durance as Alura Zor-El , Calista Flockhart as Cat Grant, Shane Kim as a soldier, Yael Grobglas as Gayle Marsh / Psi, Carl Lumbly as M'yrnn J'onzz, Gelsea Mae as a staffer and Adrian Pasdar as Morgan Edge. They will be joined by Marc Senior as another staffer and Emma Tremblay as Ruby. The other "Supergirl" cast members such as Jeremy Jordan (Winn Schott) and Chris Wood (Mon-El), will also be seen with them.

'Supergirl' episodes

The episode prior to "Girl of Steel" was the "Supergirl" season 2 finale titled "Nevertheless, She Persisted," which aired in the US on May 22. It was directed by Glen Winter. The story was written by Jessica Queller and Andrew Kreisberg, while the teleplay was written by Robert Rovner and Caitlin Parrish. It showed Rhea (Teri Hatcher) using Silver Kryptonite to manipulate Kal-El / Superman (Tyler Hoechlin) into thinking that Kara is General Zod. Supergirl was able to bring her cousin to the Fortress and end Rhea's manipulation of him.

Meanwhile, Kara challenged Rhea to Dakkam Ur, an ancient rite wherein leaders duel and the loser must concede the war. As for Lena, she helped build a machine that disperses lead which is lethal to Daxamites. The Department of Extranormal Operations (DEO) was instructed to use the device if Kara loses. Unfortunately, Rhea doesn't want to stop the invasion and the war even if she loses during the Dakkam Ur. Kara had no choice but to launch the lead device. She also sent Mon-El to safety in a pod that travelled away from Earth.

"Super girl" episodes will air again on Fox 8 in Australia starting on Tuesday, Oct. 10. It airs on The CW in the US every Mondays at 8-9 pm ET/PT. The next episode after "Girl of Steel" is "Triggers" and it will air in the US on Oct. 16.

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Source: The CW Television Network/YouTube