The trivia items below may give away important plot points.
Cynthia Addai-Robinson was crying for real during Crixus' death scene, basing it upon her own father's death who had passed away from cancer just a few months prior to filming. As close friends on set, Manu Bennett, who was previously unsure on how to play the scene, then focused his performance on giving Cynthia his look of support when Crixus gazes at Naevia before his beheading, rather than anything about himself. The photo of Crixus and Naevia with their foreheads together was not a part of the scene but after, as Robinson was still crying after filming was finished.
In the history of Spartacus, Crixus and 30,000 followers separated from Spartacus with intent on plundering the Roman countryside and perhaps marching on Rome. But, Crixus came under attack from a Roman army under the command of the Roman consul Lucius Gellius Publicola near Mount Garganus in 72 B.C. Crixus is said to have fought bravely in a losing effort, but was killed in the conflict.