|“||"Life's a dragon. You have to tame it or it'll burn you."||”|
—Simeon Swann, The Key of Bones
Eva Starling believed Ursula had followed Simeon into the Neverside and regarded what he had done as foolish.
30 years later, Simeon returned to the Dayside and used magic to get rid of a group of Witch Hounds. Here he was reunited with Ursula and also met his grandson Tom, son-in-law Michael and Tom's friend Katie Lord. After Ursula was taken by a Neverside witch named Old Bethesta, intending to use her magic to resurrect her two daughters who had been turned to stone by Caractacus Crowe, he, along with Tom, Katie and Michael, set out to find her. Simeon was saddened when Tom and Michael told him that Helen had died and said that Michael and Tom are a good father and son. Whilst Tom goes off with Katie, Simeon and Michael go off with a journalist named Laura Piper (who unknown to them is Lyzera) who magically takes a drop of Simeon's blood. Simeon and Michael find Katie standing outside a door waiting for Tom and they go through it into Bethesa's lair and find Tom cradling a dying Ursula who had most of her magic taken by Bethesa's daughters. But luckily, Simeon is able to save her by magically kissing her and, following this, the two reconcile.
Whilst out in a field, Simeon tells Tom that whilst in the Neverside, he was able to tame a Dragon. A tear in the Line of Twilight appears and Simeon and Tom are able to capture a Faery and bring it back to the Chamber of Crowe. However, Ursula is cross with Simeon for putting Tom in potential danger. Meanwhile, Lyzera, using the blood sample, invades Simeon's dreams and finds out that the Key of Bones has the power to heal or destroy the Line of Twilight. After visiting Helen's grave, Simeon returns to the Clarke household, only to overhear Ursula and Michael saying how they don't know whether to trust him or not. Simeon is upset and storms out of the house but is convinced by Tom to show how much he loves Ursula. Simeon suggests that they go on a quest to find the Key of Bones. After casting a sleeping spell on Randal Moon, Simeon uses the Faery to transport him, Tom and Michael to Shanghai. They soon run into Varg and Lyzera and end up walking through a portal to a threshold of enchantment. They meet the Quest Master and embark on a series of challenges before the Nekross leave them trapped. They are freed by Ursula who, now knowing how much Simeon really loves her, joins them on the quest. When Tom finally wins the Key of Bones, Lyzera smashes it to pieces leaving them with only one chance of saving the Line of Twilight, by getting someone to take the remains of the Key into the Neverside. Simeon volunteers in order to keep his family safe, and, after a tearful farewell with Tom, Ursula and Michael, where he tell Tom that he is a great wizard even, though that he is afraid of his own magic and to protect the dayside (the human world). He leaves for the Neverside once again.
- Simeon wields a magical staff similar to that of Ursula's staff.
- It is unknown how Simeon lived in the Neverside for 30 years of normal time, due to the fact that it would be millions of years in the Neverside.