This week fans have been treated to a slew of news from the Arrow-verse, as the CW's four interconnected series get together to film this year's crossover event. Arrow, The Flash, Legends of Tomorrow and Supergirl will all come together this fall, with the crossover event scheduled to fall on Arrow's 100th episode (the 8th in the upcoming fifth season). We've already learned that both Deathstroke and Robert Queen (Jamey Sheridan) will be returning for this episode, along with Katie Cassidy's Black Canary. The episode has also been revealed to have "no Flashpoint, no flashbacks", leading many to wonder how exactly these characters will be making their return to the series.

Now, another deceased character has been revealed to be coming back to the show for this 100th episode extravaganza, and it looks like a Queen family reunion is in the works.

EW has learned that Susanna Thompson will also be returning to Arrow as Moira Queen, mother to Oliver (Stephen Amell) and Thea (Willa Holland). No further details have been revealed, so we do not yet know how she will be returning, or if her return will extend past the 100th episode and into the rest of the fifth season.

Moira Queen was a major character for the first two seasons of Arrow, before she was brutally murdered by Deathstroke (Manu Bennett) at the end of season 2. Without flashbacks or Flashpoint to explain her return (and with the Lazarus Pit destroyed), the fan-favorite theory right now is that Team Arrow will find their way back to Earth-2, where it is possible that neither Moira nor Robert have died. Deathstroke's appearance has also been sparking speculation, especially as he is the one who killed Moira on Earth-1. Another option is that Rip Hunter (Arthur Darvill) will take the team back in time, where Oliver and Thea could meet their younger, still-living parents. Although the cast is clearly enjoying teasing fans with these reveals, they aren't giving anything away that will let us know exactly what to expect when the episode airs.

Slade Wilson kills Moira Queen Arrow

A return to the days of Deathstroke and the Queen family has many fans excited, as it suggests a return to Oliver's roots, and the Green Arrow's original mission to clean up the city and bring those who failed it to justice. This could also mark some big changes for Arrow, especially if some Earth-2 characters bleed over into Earth-1. Should Robert or Moira return for more than a single episode, that would be a game-changer for the team dynamic. These returns are also getting fans excited for another early-season character that we would all love to see again - Tommy Merlyn (Colin Donnell).

Of course, with absolutely no idea how these family members will be returning, or how long they will be sticking around, it's hard to get too excited. While some are looking forward to a return to the Green Arrow's roots, others would prefer to see something new for the 100th episode, rather than a re-tread of old characters and storylines. Arrow has had its ups and downs, and this season is a chance for the show to regain some of the fans that it lost in recent years - and to finally wrap up those hated flashbacks! No matter where the show goes, we're thrilled to see Thompson again and find out what brings Moira Queen back to Star City, even if we have to wait a couple of months for the 100th episode to air.

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The Flash season 3 will premiere Tuesday October 4 at 8pm on The CW, Arrow season 5 will premiere in the same timeslot on Wednesday October 5, Supergirl season 2 on Monday October 10, and Legends of Tomorrow season 2 on Thursday October 13.

Source: EW