Ep 16. Safe House

Sam and Dean Winchester return in the 16th episode of Supernatural's 11th season, titled "Safe House." The episode opens with the brothers investigating a brutal murder that they think could be the work of a ghost. To their surprise, they discover that the ghost is actually that of a former hunter named Gavin, who had died in the 1700s. Gavin had been summoned to the present by a witch, and he has been trying to communicate with his fiancé in the 1700s ever since.

The brothers decide to help Gavin and take him to a safe house. However, they soon discover that the safe house is not safe at all. It has been used by hunters for generations, and it is filled with supernatural traps and mechanisms designed to keep ghosts from escaping. As they try to unravel the mystery behind Gavin's summoning, the brothers soon realize that the safe house is haunted by the ghosts of two former hunters who were killed there.

As they investigate, the brothers discover that the hunters had been falsely accused of killing an innocent woman, and that they had been executed by the witch who summons Gavin. The brothers decide to solve the mystery and put the ghosts to rest, but they soon realize that the witch who summoned Gavin is still alive and is still in possession of powerful dark magic.

Meanwhile, Crowley is trying to gain control of Hell again after being banished by Lucifer. He sends his demon minions to find and retrieve the soul of a powerful angel who, when consumed, will grant him the power to take over Hell once again. However, when the demons retrieve the soul, they discover that it has been claimed by the angel Castiel, who is still recovering from being brutally beaten by Lucifer.

As Crowley tries to persuade Castiel to give up the angel's soul, he realizes that Castiel has been working with Metatron, the former scribe of God, who is now living as a human on Earth. Together, Castiel and Metatron work to find a way to banish Lucifer to another world, but the angel's power is weakened by his recent injuries.

The episode ends with Sam and Dean successfully putting the ghosts to rest and restoring Gavin's soul to its proper place in time. However, they are left to deal with the aftermath of Crowley's attempts to regain control of Hell and Castiel's weakened state.