Here's as far as I got, after looking at the optional clue:
Funqrf bs tenl: FYNGR, PUNEPBNY, FVYIRE
Qenpbavp perngherf: JLIREA, JLEZ, QENXR, UNGPUYVAT
HF pvgvrf: JNFUVATGBA, PUNEYBGGR, OBFGBA, PBYHZOHF, TNVAFOBEB
K-Zra ynfg anzrf: TERL, FHZZREF, ZPPBL
(JBEGUVATGBA?)
Nsgre gung V ybbxrq guvatf hc. V qvqa'g xabj gur K-Zra jryy rabhtu gb xabj jub Jbeguvatgba jnf.
V nyfb jnf hasnzvyvne jvgu gur pbybe Tnvafobeb. Gung frrzf yvxr gur zbfg yvxryl guvat gb zbir sebz gur Pvgvrf gb gur Funqrf bs Tenl. Ohg npghnyyl V'z fgvyy abg gbgnyyl fher, nf nccneragyl gurer'f n abiry naq zbivr pnyyrq "Puneybggr Tenl", n znepu pnyyrq "Jnfuvatgba Tenlf", naq erfhygf sbe "Jnfuvatgba Terl", "Pbyhzohf Terl", naq "Obfgba Terl" nf pbybef. Ohg znlor vg'f whfg gung rirel cbffvoyr jbeq sbyybjrq ol n pbybe unf orra hfrq nf n pbybe anzr ol fbzrbar be bgure.
Nyy bs gubfr pvgvrf ner whfg ovt HF pvgvrf, ohg V jbaqre vs gurer'f fbzrguvat ryfr tbvat ba gurer, rfcrpvnyyl fvapr V'z hafher jung gur "Svefg" va gur bcgvbany pyhr zvtug zrna.
Znlor gurl'er nyy crbcyr jub cerprqr n qenzngvp eriryngvba jvgu n dhnyvsvre. (Trbetr) Jnfuvatgba fnlf "V pnaabg gryy n yvr," Pbybzob fnlf "Whfg bar zber guvat," Puneybggr (Oebagë) fnlf "Ernqre," naq nf sbe Obfgba… jryy! jung vf zl ubzrgbja – gung tenl qenpbavna zhgnag bs n pvgl, gung pvgl nsenvq gb xabj vgfrys – jung vf Obfgba, V fnl, ohg bar cebybatrq dhnyvsvre, nakvbhfyl naq snfgvqvbhfyl njnvgvat vgf terng eriryngvba gung znl arire pbzr?