According to one critic, "the first time we really see Ziva's soft side is during season 4", when she develops a short but intense friendship with Lt. Roy Sanders (Matthew Marsden), who had been intentionally exposed to radiation by a co-worker, in "Dead Man Walking". Ziva knew him from her daily run, during which they always passed by each other running in opposite directions. This elicits concern from Tony and others when it becomes clear that she is "falling in love with a dying man". Roy later asks if she would have noticed him if he had just stopped running, expressing regret that they had never been able to "run together". Ziva assures him that she will never forget him now and, after his death, she is shown frequently wearing the orange beanie that Lt. Sanders wore when he went running.