Chap­ter XV opens on a bleak and bound­less plain, where David Innes and Dian emerge into a world both for­eign and unfor­giv­ing. With­out famil­iar land­marks, the vast­ness feels dis­ori­ent­ing, but also symbolic—a reminder of how much still lies unknown in Pel­lu­ci­dar. The pres­ence of lidis, enor­mous four-foot­ed beasts used as mounts by dis­tant tribes, intro­duces new allies and threats all at once. These nomadic rid­ers, ini­tial­ly wary, offer insights into the scale and diver­si­ty of civ­i­liza­tions buried beneath Earth’s crust. Innes quick­ly learns that uni­ty will be their only defense against the rul­ing Sagoths and the intel­li­gent yet cold-blood­ed Mahars. Every alliance formed becomes a step toward lib­er­a­tion, though ten­sions always sim­mer. Trust remains a scarce and frag­ile cur­ren­cy in this under­ground world.

As plans take shape, the idea of coali­tion war­fare feels both rev­o­lu­tion­ary and nec­es­sary. Innes is no longer just a visitor—he’s a com­man­der, strate­gist, and sym­bol of hope for many oppressed groups. Tribes once divid­ed by ter­ri­to­ry or tra­di­tion now face a shared ene­my, forc­ing them to adapt not just their weapons but their think­ing. The bat­tles described are not sim­ply about mus­cle but coor­di­na­tion, tim­ing, and learn­ing from mis­takes. Against the Sagoths, raw strength alone isn’t enough. Strat­e­gy must evolve, and with it, a deep­er sense of iden­ti­ty and uni­ty. Dian’s pres­ence grounds Innes emo­tion­al­ly, giv­ing him both a per­son­al rea­son to fight and a vision for a future beyond sur­vival. When Dacor reap­pears, bonds of fam­i­ly rein­force the grow­ing sense of human resilience in the face of alien dom­i­nance.

How­ev­er, progress is not with­out dis­rup­tion. Per­ry, always think­ing toward the future, pro­pos­es a dar­ing idea: return to the sur­face, gath­er tech­nol­o­gy, and return with knowl­edge that could shift the bal­ance in Pel­lu­ci­dar. The plan brims with promise—an infu­sion of mod­ern sci­ence into a prim­i­tive world—but its exe­cu­tion proves risky. As the par­ty pre­pares to depart, Hoo­ja, ever deceit­ful, enacts a plan that near­ly destroys every­thing. His failed kid­nap­ping of Dian results in a Mahar being trans­port­ed instead, a twist that shakes the foun­da­tion of their hopes. The idea that a hos­tile, intel­li­gent crea­ture now has access to Earth­’s sur­face is chill­ing. It rais­es ques­tions about what bound­aries have been bro­ken and whether they can be repaired. The dan­ger is no longer con­tained with­in Pellucidar—it now risks spilling out­ward.

The sud­den relo­ca­tion of Innes to the Sahara desert comes not as tri­umph but as error, leav­ing him strand­ed and iso­lat­ed. The prospec­tor, a once-hope­ful device of free­dom, becomes an iron­ic agent of sep­a­ra­tion. Instead of bring­ing help back to Pel­lu­ci­dar, it leaves Innes marooned on the wrong side of the plan­et. His long­ing for Dian trans­forms into anguish. He under­stands that return­ing will require not only inge­nu­ity but luck and the resolve to endure fail­ure. The sur­face, once a place of com­fort, now feels bar­ren com­pared to the vivid urgency of the world he left behind. For Innes, home is no longer defined by geog­ra­phy but by purpose—and that pur­pose lies deep beneath his feet.

This chap­ter makes clear that the stakes are no longer personal—they’re plan­e­tary. The effort to free Pel­lu­ci­dar isn’t about rebel­lion for its own sake; it’s about rewrit­ing the terms of exis­tence. From under­ground revolts to inter­species strat­e­gy, the world expands rapid­ly, demand­ing that its heroes grow along­side it. Even small betray­als echo loud­ly in a set­ting where trust is vital to sur­vival. Hooja’s decep­tion reminds us that progress can be undone not only by ene­mies, but by those clos­est to us. And Perry’s vision of tech­no­log­i­cal uplift high­lights the dual edge of innovation—it can heal, or it can dis­rupt in ways no one can pre­dict.

As Innes looks across the Sahara, a place he once might have seen as the end of the world, his thoughts turn inward. His jour­ney is no longer dri­ven by chance dis­cov­ery, but by con­vic­tion. If he is to return to Pel­lu­ci­dar, it must be with inten­tion, knowl­edge, and an under­stand­ing of the frag­ile alliances that make peace pos­si­ble. He rec­og­nizes now that the fight is not only against Mahars and Sagoths, but against despair and divi­sion. The human spir­it, test­ed by dis­tance and dark­ness, finds its strength not in vic­to­ry alone, but in the deci­sion to keep going. Even strand­ed and alone, Innes believes he will find his way back—not just to Dian, but to the mis­sion they began togeth­er. This chap­ter becomes not only a tale of sur­vival, but a dec­la­ra­tion of pur­pose.