Assuming this small fleet was not a threat Nicias worked on his wall, while the Spartans secretly used their allies to increase their force to 3000 infantry and 200 cavalry. They arrived in Syracuse in late 414 and started to construct a wall to counter the wall being built by the Athenians. Lamachus, was killed in a skirmish trying to defend the Athenian wall.
Nicias, now the sole commander and ill with a kidney ailment, realized he would never be able to take the city. He asked to be relieved, but was sent reinforcements under the command of Demosthenes. Not wanting to wait for Nicias to be reinforced, the Spartan commander Gylippus attacked the Athenian fleet in Syracuse harbor and defeated them. Soon after, Demosthenes arrived with plans for an immediate attack, but his two land assaults were unsuccessful during the spring of 413.