Avalon Harmonia (Cyndi Lauper) is heading back to the Jeffersonian in the final season of the Fox series "Bones."

As per Enstars, the American singer/songwriter will reprise her role as the psychic who has helped Brennan (Emily Deschanel) and the others solve particular cases that bordered on the spooky side. Avalon was introduced to the Jeffersonian people by Angela (Michaela Conlin). She first appeared in Season 5, when she helped the team discover a mass grave. Lauper's character recurred for three more episodes since then. She also sang during Booth (David Boreanaz) and Brennan's wedding back in Season 9.

Since Avalon is returning to the Jeffersonian, the fans can expect another eerie episode where her skills as a psychic will come into play. Most of the team members had doubts about her "powers" in the past, but they soon changed their minds after her "vibrations" proved to be spot on. What kind of case will Brennan's team handle that will require Avalon's help? Incidentally, another wedding is coming up for the squad. Cam (Tamara Taylor) and Arastoo (Pej Vahdat) will be tying the knot in Season 12. Could Avalon be persuaded to sing a song or two?

Meanwhile, another returning character to look forward to is Sully (Eddie McClintock), Brennan's ex boyfriend who (as per spoilers) will come to settle some unfinished business with her. They parted long before Brennan met and married Booth. Could Sully still be hung up on their failed relationship?

He left quite abruptly when Brennan refused to leave Washington, D.C. with him. He wanted her to run away with him, but she was already starting to love her job at the Jeffersonian that time. It will be interesting to see how Booth will react once he meets Sully. Will he feel threatened by his wife's ex?

The final season of "Bones" will air in 2017 on FOX.