After the events of The Dance Barrage was captured by the council and had his memories wiped. Cassandra later reinstated him as principal but placed a special micro chip in his neck so she could control him using her phone, as revealed in Fight or Flight. When the chip is activated Barrage's cyber eye vision turns from red to blue and he mindlessly obeys any order he is given ignoring anyone else around him. He has no memory of anything he has seen or done after the chip is deactivated. In Pyramid Scheme Barrage becomes suspicious of all these gaps in his memory and upon studying the surveillance camera footage of himself realizes that he is being controlled. He unscrews his neck plate and attempts to remove the chip but this only causes his circuitry to malfunction sending him into a mad rage until he is put into sleep mode by Finnwich, seemingly because Finnwich created his robotic parts.
The control chip has the Mann, Wurst and Finnwhich logo and interestingly what appears to be the three bars symbol seen in the Book and Lee's tatoo.