The TARDIS in our Mind Palace (The New Companion)

The Fault in our Stars meet Doctor Who and Sherlock.
*For your information it includes spoilers*

After Agustus's death Hazel is heartbroken and the Doctor is alone in his TARDIS once again. It can only mean one thing. Does Hazel become The Doctor's new companion?

However was Hazel told the truth about Agustus and when he turned out to be the grenade was it really just Moriarty playing with their relationship? Sherlock is the only one who can find out. But what about The Doctor?

Can The Doctor help Hazel battle through cancer or does he even know she has it? When he finds out will it be too late and yet again he will be left alone?