Artemis- Call Tracing

“The message is from
Juliet,” he said, consulting the three-inch touch screen.
Butler’s pique immediately evaporated. “Juliet sending an
emergency message? What does it say?”
Artemis wordlessly handed over the phone, which seemed to shrink
as Butler’s massive hand enfolded it.
The message was short and urgent. Five words only.
In trouble, Domovoi. Come alone.
Butler’s fingers squeezed the phone until its casing cracked. The
first names of all Blue Diamond bodyguards were closely guarded
secrets, and the mere fact that Juliet had invoked his name to summon
him was an indicator of how much trouble she was in.
“Naturally I’m coming with you,” said Artemis briskly. “My phone
can trace that call to the nearest square centimeter and we can be
anywhere in the world in just less than a day.”

- The Atlantis Complex, Chapter 2