Block's search for Wally leads him to Mach X's impenetrable skyscraper in New York City. Outside the gates, a military battalion of SoldierBots guards an encampment of trapped human survivors.

Block embarks on a bold mission - to infiltrate the tower in a bid for Wally's freedom - a mission for which the cost may prove too high to bear. Will Block succeed in his bid for freedom, or will he be crushed by the combined might of Mach X's forces?

Steel Siege is Book 4 in the award-nominated Rusted Wasteland series.