Igor Sergei Valenko (Bentley Calder) was a KGB agent with ties to Irina Derevko. Like Irina, he faked his death.
Before Season 1
Igor was working for the KGB along with Irina Derevko, earning the nickname "Spy Hunter". Somewhere along the line, he feigned his death along with Irina.
Several years later, he joined the FBI under a new name and face: Bentley Calder. However, Calder was secretly working with Khasinau, heading his money laundering business in Cape Town.
K-Directorate placed a hit out on Khasinau and sent a hitman nicknamed Snowman to kill him. Since the Snowman couldn't locate Khasinau, he decided to look for one of his contacts, which happened to be Calder. Sydney and SD-6 also realized that Calder was in danger and needed to find him fast, so they sent Sydney to Australia. Unfortunately, Sydney was only a few minutes too late; she found all of Calder's guards dead and as soon as she entered the kitchen, she saw the hitman stabbing Calder.