Here are a few hints for fire+key, in ROT13 (https://rot13.com/). Each line is a separate hint, in each section the hints get increasingly more specific.
General stuff:
Lbh pnaabg trg vagb gur yrsg fvqr bs gur yriry hfvat bayl sver; ng yrnfg bar hfr bs xrl vf erdhverq.
Ohg vs lbh hfr xrl gjvpr, gur gbjre bs svir oybpxf jvyy pbyyncfr naq lbh jba'g or noyr gb pbzcyrgr gur abegujrfg fgne.
Fb lbh zhfg hfr xrl rknpgyl bapr gb trg vagb gur jrfgrea nern.
The first step:
Ubj ner lbh tbvat gb trg gur xrl beo bhg bs vgf mbar jvgubhg hfvat vg? Gur boivbhf ebhgrf jvyy pnhfr lbh gebhoyr, ohg gurer vf nabgure jnl.
Lbh jvyy unir gb trg gur fbhgurnfg fgne jvgu sver nybar orsber lbh teno gur xrl beo.
Erzrzore gung lbh pna hfr gur ubzr fcryy.
The second step:
Lbh jvyy arrq gb hfr gur xrl, gura ohea n ybpxrq tngr.
Gur tngr zhfg or ohearq sebz nobir.
Abg nyy yrsg-hc cnguf ner perngrq rdhny.
Va cnegvphyne, tbvat yrsg gjvpr naq gura hc jvyy abg gevttre gur xrl.
The third step:
Bapr lbh unir tbar guebhtu gur ghaary, vg'f n tbbq vqrn gb bcra gur bar-jnl qbbef, gubhtu or pnershy abg gb ybfr lbhe xrl va qbvat fb. Qb lbh frr nal vagrerfgvat cynprf jurer lbh pbhyq hfr gur xrl?
Trggvat hc bagb gur jnyyf jbhyq frrz gb or n tbbq vqrn.
Bapr lbh ner ba gur jnyyf, gurer vf bar cnegvphyne tngr gung jvyy uryc lbh ernpu lbhe tbny, gubhtu vg znl or qvssvphyg gb fcbg.
Vf gurer nalguvat lbh pna ernpu jvgu n yrsg-hc zbir gung lbh pbhyq abg unir ernpurq orsber?