When DrJava reaches a breakpoint during a method call, it prints a new prompt to the Interactions Pane. This new interpreter has the context of the program which has been suspended, including all variables, fields (even "this"), and methods that are in scope in the suspended method. (The prompt text itself contains the name of the thread which has been suspended. In most cases, this name will include the text being interpreted.) You can type the name of any variable or field to view its value or assign it a new value, or you can call any method in scope to observe its behavior. Existing lines of code in the program cannot be changed or skipped, however, and the "return" keyword is not available. Any changes you make to variables or fields will be reflected in the program when it resumes execution, either by stepping or resuming.