From the text of "Romeo and Juliet", isolates the characters by tagging them as PERSON and then using the Tag Filter node to keep only PERSON terms. These will be the nodes of your network. You might want to add the frequency of such terms for the node size. Then run the Term co-occurrence counter node to count the isolated terms (PERSON) occurring together in a sentence (the speaker and the addressee). These will be your edges. Finally build the network and visualize the graph.