The truce between the groups lasted almost one year, until a virus was found in one of the bandit computers. Now we have to start a fierce battle in Metal Slug 4, in order not to let the cyber attack spread to the main server. The threat of destruction is strong, that can absorb not only the computer system of thieves in the law, but become dangerous for the corporation"Anteus", which oversees the country's Internet networks. Trevor Spacey and Kassel Nadia are already in full arms and ready to rush along with you on intruders. Do not make your team wait, immediately leave the comfort zone and start fighting against adversaries.