Jake glanced down at his wrist and was surprised all over again by a memory of the Tick-Tock Man’s catlike green eyes when he saw not his watch but only the place where it had been—a white shape outlined by his deeply tanned skin. How much longer did they have? Surely no more than seven minutes, and that was being generous. He looked up and saw that Roland had removed a cartridge from his gunbelt and was walking it back and forth across the knuckles of his left hand. Jake felt his eyelids immediately grow heavy and looked away, fast. “What voice would you remember, Susannah Dean?” Roland asked in a low, musing voice. His eyes were not fixed on her face but on the cartridge as it did its endless, limber dance across his knuckles . . . and back . . . across . . . and back . . .
He didn’t need to look up to know that Jake had looked away from the dance of the cartridge and Susannah had not. He began to speed it up until the cartridge almost seemed to be floating above the back of his hand. “Help me remember the voice of my father,” Susannah Dean said.
FOR A MOMENT THERE was silence except for a distant, crumping explo-sion in the city, the rain pounding on the roof of the Cradle, and the fat throb of the monorail’s slo-trans engines. Then a low-pitched hydraulic hum cut through the air. Eddie looked away from the cartridge dancing across the gunslinger’s fingers (it took an effort; he realized that in another few moments he would have been hypnotized himself) and peered through the iron bars. A slim silver rod was pushing itself up from the sloping pink surface between Blaine’s forward windows. It looked like an antenna of some kind. “Susannah?” Roland asked in that same low voice. “What?” Her eyes were open but her voice was distant and breathy—the voice of someone who is sleeptalking.
“Do you remember the voice of your father?” “Yes . . . but I can’t hear it.”
“SIX MINUTES, MY FRIENDS.”
Eddie and Jake started and looked toward the control-box speaker, but Susannah seemed not to have heard at all; she only stared at the floating cartridge. Below it, Roland’s knuckles rippled up and down like the heddles of a loom. “Try, _Susannah,” Roland urged, and suddenly he felt Susannah change within the circle of his right arm. She seemed to gain weight . . , and, in some indefinable way, vitality as well. It was as if her essence had somehow changed. And it had.
“Why you want to bother wit dot bitch?” the raspy voice of Detta Walker asked.
DETTA SOUNDED BOTH EXASPERATED and amused. “She never got no better’n a C in math her whole life. Wouldn’ta got dat widout me to he’p her.” She paused, then added grudgingly: “An’ Daddy. He he’ped some, too. I knowed about them forspecial numbahs, but was him showed us de net. My, I got de bigges’ kick outta dat!” She chuckled. “Reason Suze can’t remember is ’cause Odetta never understood ’bout dem forspecial numbers in de firs’ place.” “What forspecial numbers?” Eddie asked.
“Prime numbahs!” She pronounced the word prime in a way that almost rhymed with calm. She looked at Roland, appearing to be wholly awake again now . . . except she was not Susannah, nor was she the same wretched, devilish creature who had previously gone under the name of Detta Walker, although she sounded the same. “She went to Daddy cryin an’ carryin on ’cause she was flunkin dat math course . . . and it wasn’t nuthin but funnybook algebra at dat! She could do de woik—if I could, she could—but she din’ want to. Poitry-readin bitch like her too good for a little ars mathematica, you see?” Detta threw her head back and laughed, but the poisoned, half-mad bitterness was gone from the sound. She seemed genuinely amused at the foolishness of her mental twin. “And Daddy, he say, Tm goan show you a trick, Odetta. I learned it in college. It he’ped me get through this prime numbah bi’ness, and it’s goan he’p you, too. He’p you find mos’ any prime numbah you want.’ Oh-detta, dumb as ever, she say, ‘Teacher says ain’t no formula for prime numbahs, Daddy.’ And Daddy, he say right back, ‘They ain’t. But you can catch em, Odetta, if you have a net.’ He called it The Net of Eratos-thenes. Take me over to dat box on the wall, Roland—I’m goan answer dat honkey computer’s riddle. I’m goan th’ow you a net and catch you a train-ride.”
Roland took her over, closely followed by Eddie, Jake, and Oy. “Gimme dat piece o cha’coal you keep in yo’ poke.” He rummaged and brought out a short stub of blackened stick. Detta took it and peered at the diamond-shaped grid of numbers. “Ain’t zackly de way Daddy showed me, but I reckon it comes to de same,” she said after a moment. “Prime numbah be like me—ornery and forspecial. It gotta be a numbah don’t newah divide even ‘ceptin by one and its own-self. Two is prime, ’cause you can divide it by one an’ two, but it’s the only even numbah that’s prime. You c’n take out all the res’ dat’s even.”
“I’m lost,” Eddie said.
“That’s ’cause you just a stupid white boy,” Detta said, but not unkindly. She looked closely at the diamond shape a moment longer, then quickly began to touch the tip of the charcoal to all the even-numbered pads, leaving small black smudges on them.
“Three’s prime, but no product you git by multiplyin three can be prime,” she said, and now Roland heard an odd but wonderful thing: Detta was fading out of the woman’s voice; she was being replaced not by Odetta Holmes but by Susannah Dean. He would not have to bring her out of this trance; she was coming out of it on her own, quite naturally.