One weekend that summer, Denny finds a teaching job in Spokane, and Mike arranges for Enzo to spend the weekend with Zoë, Trish, and Maxwell. The night that Enzo arrives, he finds his bed already in Zoë's room. He dozes off and later wakes to find Zoë also awake, busy stacking her stuffed animals in a tall circle around Enzo's bed. She whispers to Enzo that they'll keep him company, and Enzo finds it amusing and touching. He falls asleep again. Later in the night, Enzo stirs and notices that on top of the pile, staring at him, is the replacement zebra, its eyes glinting. Enzo tries to stay awake to keep an eye on it, but keeps drifting off, only to wake again and find the zebra still staring.
The zebra's resurrection here while Enzo is well-fed and in his right mind acts as a symbol for evil or mayhem to come. Notice that it doesn't attack Enzo, Zoë, or any of Zoë's possessions-- it just watches Enzo and creates a sense of surveillance and discomfort. Further, it still seems to be Zoë’s favorite, which complicates Enzo's perception that it's pure evil since it's loved by someone he loves and cares for greatly.
The following afternoon, as Enzo naps on the porch while Trish and Maxwell drink their afternoon cocktails, he overhears their conversation. Trish wonders if Annika isn't as innocent as she's making out to be, and Maxwell is livid. Trish points out the coincidental timing of the rape suit, and Maxwell retorts that he'll use any opportunity to keep Zoë.
Trish continues to indicate that she'd rather not fight over Zoë. She may be a more sympathetic character than Enzo or the reader gave her credit for, despite her willingness to go along with Maxwell.
Enzo, stunned, thinks that despite their clever tricks, they don't understand Denny's persistence. He continues to fume and decides that Trish and Maxwell are now the Evil Twins, and his anger fuels a thirst for revenge. When Maxwell pulls out his favorite peppers, Enzo begs and Maxwell offers him one. Enzo decides against biting Maxwell but takes the pepper, telling the reader he's not above using the fact that he's "just a stupid dog" to exact revenge.
In this situation, Enzo plots how to use his dog-ness as a tool or a weapon and doesn't see it as something bad. He's willing to play the part of a "stupid dog" to win this fight. Enzo creates some dramatic tension when he takes the pepper, as the reader knows or suspects the consequences, unlike Maxwell.
When Maxwell opens the door to let Enzo outside later that night, Enzo thinks about what Maxwell is doing to Enzo's family. Enzo crouches right there on the expensive, light-colored carpet and lets loose a pile of pungent diarrhea. When he's finished, he runs happily to Zoë's room and growls at the zebra. Enzo says the zebra understood, and the demon knew not to mess with him that night or ever again.
By exacting revenge on Maxwell and Trish, Enzo is also able to get even with the demon zebra. By purposefully leaving his foul mess on Maxwell's carpet, Enzo arguably tapped into the bit of the zebra that's within him, although he hasn't made this connection yet.