The series begins the stage without the participation of the main characters: the audience is shown the aircraft, full of sleeping passengers, in which a little girl wakes up. It seems that the plane suffers a wreck: the door to the cockpit is open, but no one manages the plane - pilots unconscious or dead. A mobile phone of one of the passengers is ringing, the girl takes the phone and hears the voice of Moriarty, who says: "Hello, my name is Jim Moriarty and this is the last problem, welcome."
Mycroft, who is madly afraid of the EVR, the efforts of Sherlock and John find out that the sister is alive and free. Mycroft tells them that the EVR, being, unlike the brothers, a real genius, ended up in a mental hospital called Sherrinford (so no third brother named Sherryford, alas, will not). During the meeting of Mycroft, John and Sherlock, someone makes another attempt on them - this time with the help of grenades, fleeing from which, the Trinity jumps out of the window.
Sherlock, Maikroft and John are sent (or rather to say, make their way) to Sherrinford. Sherlock meets with a sister, which as a result attacks him. Guards of the hospital, meanwhile, immobilize Watson.
In Flashbek, the audience shows the events of 5 years ago - Moriarty comes to the hospital and uses the EVR for its frauds.
Mycroft, Sherlock, Watson locked in the chamber, they are associated with that very girl in the plane, which we have seen at the beginning of the series. The EVR, however, does not give them how to talk, demanding from our Trinity in exchange for a conversation with the girl to perform a number of tasks. One of the tasks is to "knock out" from Molly Recognition in love, with which Sherlock successfully copes, speaking to her "I love you" - hello, thereby the trailers that blew up a few weeks ago.
Sherlock finds out that an unmanaged aircraft with a girl flies directly to London. Sherlock will have the following test - to save Watson, who is chained to the bottom of the well, in which the water begins to rise. Sherlock guess that they were moved somewhere from Sherriford somewhere in another place and eventually finds out that he is at home, in the estate of Holmes.
After the next series of turns of the plot, the audience show that there was no girl and no aircraft, everything that happened was only a metaphor of the loneliness of the EVR, who was jealous of his brother and desperately wanted to reunite with him. Sherlock and EVR help John get out of the well - and the peculiar Happi-end occurs.
In a series of scenes of Epiloga, viewers show that the Evr returned to a psychiatric hospital, Sherlock periodically visits her, John returns to live on Baker Street 221b and our duet again, as once for a long time, takes visitors who need detective services.
A source