Soon after he reaches the prison camp of Jiangzhou, Song Jiang, in exile from Yuncheng as a mitigated sentence for killing his mistress, becomes friend of the chief warden Dai Zong and jailer Li Kui.

As Zhang is fair-skinned and Li is dark, their stark contrast in complexion amuses the onlookers each time they bob above the water.

Earlier, when on his way to Jiangzhou, Song Jiang met Zhang Heng at the Jieyang River, who asked him to deliver a letter to his brother.

Zhang Shun, who grew up in the Yangtze region, remembers that his mother once suffered from a similar illness and was healed by a physician An Daoquan.

An excellent swimmer, Zhang Shun frees himself under water and gets to the opposite bank, where he finds the inn of Wang Dingliu.

Zhang Shun finds An Daoquan but the physician is unwilling to leave a prostitute called Li Qiaonu whom he is besotted with.

Remembering what Wu Song did in Mengzhou, Zhang Shun writes with the blood of Li on the wall a proclamation attributed to An declaring himself to be the killer.

When the boat is midstream, Zhang Shun, who has been hiding his face, overcomes the boatman with the help of Wang Dingliu, ties him up and dumps him into the river.

Zhang Shun's swimming skills are pivotal in Liangshan's battle against the army led by Grand Marshal Gao Qiu to wipe out the stronghold.

He and his men manage to reach Gao's ships unnoticed by swimming underwater, and proceed to knock holes in their hulls, causing them to sink.

After the Liangshan outlaws received amnesty from Emperor Huizong, Zhang Shun participated in the campaigns against the Liao invaders and rebel forces on Song territory as ordered by the court.

In the battle of Hangzhou in the campaign against Fang La, Zhang Shun attempts to sneak into the city by climbing over the sluice gate of Yongjin (湧金門).