Warning: contains spoilers for The Death of Doctor Strange #2!
Despite his considerable magic powers, Doctor Strange is already failing in what is perhaps his most important mission yet: the investigation of his own murder. Marvel's Death of Doctor Strange is a crossover event which chronicles the sudden and mysterious assassination of the Sorcerer Supreme by an unknown assailant. Thanks to Strange's contingency plans, the good doctor is still alive and well even after death - though he's not exactly the Strange that his friends know and love - he's a Strange from the Silver Age of Comics.
The Death of Doctor Strange #2, written by Jed MacKay with art by Lee Garbett and colors by Antonio Fabela, returns to Doctor Strange's front door: the scene of the crime. Strange's friends (and enemies, including Baron Mordo) gather around Strange's dead body but are shocked to find a younger Strange suddenly standing before them. The doctor explains his older self's contingency plan: "I severed one week from my personal timeline, cut it from my lifespan...and I hid it away, secret from all." If anything were to happen to Strange-Prime, this Strange would put his affairs in order, and his killer found and brought to justice. To make matters worse, the Earth is immediately subject to invasions from various magical beings. Unfortunately, as Strange's friends surround him, all he sees are strangers - even Clea, Doctor Voodoo, and Zelma Stanton.
Zelma is simply an unknown 'young lady' to him. Strange is further amazed when she produces an Avengers calling card that projects a holographic display - technology obviously unknown to his time. He's even further amazed when Captain America calls him personally, and Strange realizes Steve Rogers and his older self were friends. Regarding the invasions, Strange believes the first order of business is to contact the Sorcerer Supreme. Upon realizing he is the Sorcerer Supreme - or rather, was - Strange despairs. "By the Hoary Hosts of Hoggoth. There is no Sorcerer Supreme. We are undone."
Even before investigating his future self's murder, Doctor Strange finds himself out of his depth. He has been thrust into a future decades ahead of his familiar present, in which technology had advanced considerably (and magic would likely have advanced in a similar manner). All of his friends are unknown to him, and he hasn't even met Doctor Voodoo or even Captain Marvel. Unfortunately, this means Doctor Strange effectively has zero murder suspects as far as his knowledge goes, and he's failing the investigation before it has even started.
To add insult to injury, this Strange is significantly less powerful than the deceased (and significantly less knowledgable). If Strange severed one week from his timeline in order for this contingency-Strange to exist, does that mean Strange has only one week to solve his own death before he disappears forever? If so, that's hardly any time to Doctor Strange to acclimate himself to what is effectively a brand new world.