In the chap­ter titled “Dual Warn­ing,” dat­ed Feb­ru­ary 21, sig­nif­i­cant events unfold in Wash­ing­ton and Philadel­phia sur­round­ing a poten­tial assas­si­na­tion threat against Pres­i­dent-elect Abra­ham Lin­coln. Gen­er­al Win­field Scott, after receiv­ing alerts about the threat from Dorothea Dix via rail­road exec­u­tive Samuel Fel­ton, ini­ti­ates an inves­ti­ga­tion. He enlists the help of John A. Kennedy, the head of New York City police, who has already dis­patched detec­tives to scru­ti­nize the sit­u­a­tion. Scott offers Kennedy assis­tance from Colonel Charles P. Stone, who is new­ly appoint­ed as inspec­tor gen­er­al of the Dis­trict of Colum­bia Mili­tia by Scott.

As the ten­sion builds, Kennedy’s detec­tives infil­trate South­ern cities, notably Bal­ti­more, where one detec­tive, David S. Book­staver, pos­es as a music agent and uncov­ers alarm­ing chat­ter about plots against Lin­coln. The urgency esca­lates as Lin­coln is sched­uled to arrive in Bal­ti­more soon. Gen­er­al Scott dis­cuss­es the con­spir­a­cy with Sec­re­tary of State William Hen­ry Seward, prompt­ing Seward to send an urgent mes­sage to his son, Fred­er­ick, instruct­ing him to deliv­er a warn­ing to Lin­coln in per­son.

Fred­er­ick boards a train to Philadel­phia, where he finds Lin­coln stay­ing at the Con­ti­nen­tal Hotel. Mean­while, Lin­col­n’s aide, Nor­man Judd, meets with Allan Pinker­ton, who con­veys severe con­cerns about the assas­si­na­tion plot and urges imme­di­ate action. Despite the warn­ings, Lin­coln remains dig­ni­fied and skep­ti­cal, opt­ing to stick to his planned sched­ule and address a sig­nif­i­cant pub­lic event in Philadel­phia.

Lat­er, Fred­er­ick final­ly meets Lin­coln, who reviews the reports of the con­spir­a­cy calm­ly. He ques­tions:

1. How the intel­li­gence was gath­ered.
2. The involve­ment of spe­cif­ic indi­vid­u­als regard­ing the threats.

Lin­coln express­es dis­be­lief in the plot’s sever­i­ty, con­trast­ing the dis­parate intel­li­gence sources. He insists on delib­er­a­tion before mak­ing any deci­sions. Despite the grav­i­ty of the sit­u­a­tion, Lin­col­n’s demeanor reflects a com­posed leader grap­pling with the con­flict­ing pres­sures of pub­lic duty and per­son­al safe­ty, promis­ing to con­sid­er his father’s advice about alter­ing his trav­el plans before his audi­ence with the peo­ple the fol­low­ing day .