Final answer:
Laertes intends to use the poison he has purchased to kill Hamlet during a fencing match by using a poisoned sword as part of a revenge plot orchestrated with King Claudius.
Step-by-step explanation:
In William Shakespeare's play Hamlet, Laertes plans to use the poison he has purchased in a scheme to kill Prince Hamlet. Distraught by his father's death and his sister Ophelia's ensuing madness and death, Laertes conspires with King Claudius to exact revenge on Hamlet.
The plan involves a fencing match between Laertes and Hamlet, where Laertes will use a poison-tipped sword to ensure that even a scratch would be lethal to Hamlet. In addition to the poisoned sword, Claudius prepares a poisoned cup, meant for Hamlet to drink should the sword fail to kill him.
Unfortunately, the plot eventually leads to the deaths of several characters, including Laertes himself, who dies after being wounded with his own poisoned sword.