One end of the 39K (R5) resistor is connected to the end of R1 (1K resistor) which is connected to the on/off switch, which is also connected the pins 4 and 8 of the 555 chip. The other end of R5 is connected to the end of R3 (the other 1K resistor) that is connected to the positive handhold.
Does this help you? Are you building your own Zapper?
This information is in Dr. Clarks latest book on HIV/AIDS.