Jan 6th 2017
Brennan hired Strzok to help write the Intelligence Community Assessment (ICA) on Russian interference. (Strzok was also CIA). This is where Brennan denies the use of the dossier.
https://www.dni.gov/files/documents/ICA_2017_01.pdf
Trump Inauguration: Jan 20th 2017
Strzok Interviews Flynn: Jan 24th 2017
Sally Yates “was not happy” with the bureau, according to Peter Strzok, who was one of the agents who interviewed Flynn.
https://dailycaller.com/2018/12/14/sally-yates-flynn-fbi/
June 23, 2017 Lisa Page to Strzok "Please don't ever text me again."
July 27th, 2017 McCabe goes after Strzok
“They said they had a very important matter for me to review and they needed me to come across the street and talk to them that day, which was unusual,” McCabe explained. “I made the decision to remove him from the investigation that evening.”
https://www.foxnews.com/politics/mccabe-says-he-made-the-decision-to-remove-strzok-from-mueller-team-transcript
Combined with Mueller hiding Strozks communications
DOJ-issued iPhones six months earlier when their assignments to the SCO had ended. The 010 was told that the DOJ issued iPhone previously assigned to Strzok had been re-issued to another FBI agent following Strzok's departure from the SCO. The SCO obtained the iPhone from that individual and provided it to the 010. CYB ER obtained a forensic extraction of the iPhone previously assigned to Strzok; however. this iPhone had been reset to factory settings and was reconfigured for the new user to whom the device was issued. It did not contain data related to Strzok's use of the device. SCO's Records Officer told the 010 that as part of the office's records retention procedure, the officer reviewed Strzok's DOJ issued iPhone after he returned it to the SCO and determined it contained no substantive text messages.
https://oig.justice.gov/reports/2018/i-2018-003523.pdf
Brennan/Yates/McCabe/Page were all relying on him as part of crossfire hurricane + more, and got fucked. The interview with Flynn was AFTER 2 weeks of the leaked Flynn-Kislyak leaks and all the ensuing attacks. Strzok sprang into action shortly after Trump won. The Flynn case is going to expose the FISA abuse.