Summoning Key

"The Summoning Key is one of the oldest artifacts in all creation. It was used by the first one to mix all the dimensions with life, giving each one its unique balance. Under certain circumstances, it has the ability to form bridges between dimensions allowing the transfer of life forces back and forth. It resides in the 63rd dimensions of creation."

- Excerpt 349561223 from the Kronorium

An artifact used by Primis Richtofen. It can do just about anything, if one puts their mind to it. And has an affinity for it. Lets the Doctor travel between timelines and dimensions. Which is what it was used for, seemingly, in TFR. And only for that.

Season 2
Richtofen came into the TFRverse by the guidance of the Kronorium with this device, replacing Brendan Fraser on the roster of elimination chamber. A bit later, to solidify his presence, he appeared with a certain schoolgirl in the ring that belonged to this dimension. But that schoolgirl was housing a different presence inside of her, one that Richtofen brought from a point in time before his arrival. Kirigiri's soul resided in the Key, waiting to be returned to her body.

Yet, later, plans went awry, as Adachi murdered the body of Kirigiri and threw it inside of the TV World. With the power of the Key, Richtofen was able to open a portal into that dimension and yoink Samantha's soul before it could expire. But not the body, strangely enough. So, the lone detective inside the key got herself a roommate. And both residents were not exactly happy with the situation. So had the status quo maintained throughout the Todd ordeal.

Somewhere in the finale, Richtofen promised to return Samantha back to the MPD, before the distortion grew too strong to be contained. But certain revelations that came from the Kronorium occupied his mind, and Samantha continued being a resident of the key.

Season 3
Nothing much was seen of it during the Merge. Richtofen used it to exit the TFR dimension after retrieving the The Focusing Stone. Neither Kirigiri, nor Samantha have been observed being returned to their respective places. AS such, their fate remained unknown.