Long ago, Nightingale the Robber managed to defeat Ilya Muromets by cunning. He rewrote history, appropriating all the hero's exploits and glory. Thanks to the elixir of immortality, Nightingale has survived to this day. And now he wants to revive the dark god Veles, to whom he sold his soul back then. Today, only the family of our heroes knows this secret. The heroes' father, Professor Kiselev, manages to find Muromets in the north, in the ice of an underwater cave where the last battle between the hero and the robber took place. Thanks to Kiselev's development - the steel heart - Muromets returns to our world. However, this feat costs the professor his life. Now his sons, Maxim and Yegor, must not only stop Nightingale, but also restore the good name of Ilya Muromets - in duels between giant robot warriors at the "Roboarena".
