Donna teaches Toby and Josh an important lesson as their trek homeward continues; Sam staffs the President in Josh's absence and welcomes an old friend home; Bartlet hires a secretary and C.J. finds a Big Brother for Anthony; the situation in Qumar continues to escalate; Bartlet gets spooked by a photo op as the Dow continues its dive; and a pipe bomb kills 44 students at a Midwest university swim meet.