Robert Aramayo will reprise his role as young Ned Stark for the final episode of Game of Thrones season 6, Hull Daily Mail has confirmed. Aramayo first appeared in the episode Oathbreaker which featured the first part of Tower of Joy flashback. The article also mentions that he will have a significant role in the upcoming episode [The Winds of Winter], which gives us hope of finally learning about what exactly happened when Ned found a dying Lyanna inside the tower.
** Spoilers and speculation below **
As we saw in the episode 3, Tower of Joy is a location in northern part of Dorne where Lyanna Stark was kept by Rhaegar Targaryen. At the end of Robert’s Rebellion, Ned Stark led the raid on the tower along with his companions and ‘defeated’ the guarding Kingsguards. After entering the tower, Ned found his sister dying and she claimed a promise from him before she died.
Fans believe that the promise was an infant Jon Snow and he is actually the son of the Rhaegar and Lyanna (R+L=J). Ned’s promise was to never reveal Jon’s identity as Robert would have probably killed Jon if he came to know about his true parentage and therefore raised him as his bastard son. With Jon coming back to life in the second episode, it will be interesting to see if there is any truth to the most popular Game of Thrones fan theory.
There is also an alternate version of theory which claims Lyanna had twins and we met the other twin this season. Read about it here.