Watch on Soap2day. Across The Line is a first hand account of the pressures and temptations that face vice cops while they are undercover. In the high stakes world of undercover police work, the undercover operatives walk a fine line. Where not going deep enough can get you killed, going too deep can have dire consequences as well. When the line between right and wrong starts to become unclear to an undercover cop, he must make a very difficult decision. A decision that not only affects him, but everyone else around him.