Oliver is forced to listen to his sister's torment, and faces crushing at Donna's feet...
Oliver heard Katie's blood curdling scream and desperate gurgling in search of air amid the other terrible sounds of Grace's interior, and he couldn't stop himself from vomiting the contents of his own stomach onto the insole. He threw the radio under Donna's foot, hoping she would crush it so he could stop listening to his sister's death contractions, but while it was easily crushed, the wires to the speaker held on for a few more seconds.
Oliver had never felt despair so terrifying, knowing his sister had died just feet away and he had achieved no progress towards stopping it. As he hacked out the last food he had eaten, he thought again of Carl's mangled corpse, begging for death. He knew now he should have ended it for Carl, and wished he could've done the same for Katie, if nothing else. Instead, even with all of his smarts, he hadn't been able to help anyone, and every limb and appendage on his own body was battered, bleeding, or bruised. There was no hope for any of them, he knew that in his soul. Knowing how Carl felt, he decided it was his time as well. He could at least go peacefully if during the next step he shoved his head under Donna's toe, it would be crushed instantly. He prepared himself for the final moment, but was knocked off balance at the last second.
Above, Donna had reached Grace's doorstep, and knocked. She began to tap her foot in annoyance that Grace was making her wait, pulling her phone out to check her messages. Unconsciously, she noticed a small wet spot on her left big toe, but her subconscious decided it was most likely sweat, not even a bug.
The flat tipped upwards, toe section inclined, causing Oliver to slide through his own vomit feet-first towards Donna's foot. The shoe descended fast, Donna's big toe crushing Oliver's feet and ankles into a red pudding that seeped into her grimy insole. She was tapping her feet, and each time Oliver's body descended a bit further down.
Oliver screamed in pain, vomiting again from the sheer excruciating feeling surging through his nerves, each bounce of her toes dragging a few inches more of his body into his bubbling liquified flesh pooling across her insole. Within seconds his stomach was burst, intestines and other organs sitting in the open air for a few painful moments before they too were crushed into paste. Finally, with one especially irritated shoe tap, his chest and body were pulled under Donna's toes as he let out bitter tears of relief that this nightmare was finally over.
A text from Dan popped up on Donna's phone, causing her to hover her foot as she read it. 'Hurry back, got a treat for your birthday' it read, and she smiled as she set her foot down to knock on Grace's door one final time.
As if taunting him, the big toe hovered, slowly coming down onto Oliver's face. He could feel the entirety of his skull creaking as the pressure caused his left eye to burst painfully, warm blood surrounding the remains of his body. Finally, the toe descended fully, reducing Oliver's torso to a gory mess which bubbled on Donna's toe, unnoticed as if it was some especially grimy sweat. The remains were ground into the insole as Donna turned on the tips of her toes to giddily rush back to the house, deciding she would just text Grace later since they had talked earlier.
The only thing that would remain of Oliver was a red smudge so deep in Donna's flat that most likely no one, not even Donna herself, would notice it...
...Well, that was true for... approximately 90% of his body. In actuality, his seemingly merciful death hadn't actually finished the job. While he had gone unconcsious from the pain, the sad fact is that poor Oliver was truly testing the limits of shrinking sciene and just how long it can keep you alive even with 90% of your body turned to paste. Plastered onto Donna's big toe with his own slowly hardening gore, Oliver's head and sole remaining arm were along for the ride.
With a spring in her step, Donna started her way back to the house, curious what surprise would be waiting for her.