The premiere episode of "Grey's Anatomy" season 13 will be a hot and sizzling one, as revealed by actress Debbie Allen.

Allen, who portrays Catherine Web and directed the premiere episode of the popular ABC series, recently shared on Instagram that the title of "Grey's Anatomy" season 13, episode 1 will be "Undo." The post sparked speculations that a steamy and sizzling reunion will happen between Jackson and April, especially since it is very usual for the series to incorporate outrageous elements in its episodes.

The upcoming season is also expected to focus on the storylines of its original characters, Meredith, Weber, Bailey and Alex. Fans of the series know that even after the end of so many seasons and despite the countless faces featured in the show, the importance of the original cast members did not diminish.

Kelly McCreary who portrays Maggie also previously revealed that the upcoming season will devote some time to the abovementioned characters so viewers will know where they have been and the changes that have happened in their lives all these years.

In the season 12 finale, Amelia and Owen finally said "I do," while Jo and Alex had a misunderstanding that resulted in Alex hitting Andrew DeLuca. The episode also saw a love triangle brew after Meredith slept with Nathan just when her sister Maggie had just declared her feelings for the guy.

"Grey's Anatomy" season 13 premieres on Sept. 22, 8:00 P.M. on ABC. The new series will pick up immediately after the season 12 finale.