You're all back in Heart's room. It's the evening, and the light that peeks out from her drawn curtains has slowly shifted from a soft yellow to a salmon-pink colour.
"Flower," Heart says, "We've decided on a plan."
"What is it?" Flower asks.
"Star's going to go in first. We'll attach a rope to her, so that Diamond and I can pull her out afterwards." Heart explains, "If she gets stuck inside, she's the strongest and most active out of all of us, so she'll be able to fend for herself if anything bad happens."
"Okay..." Flower says.
"So can you make another portal for us?" Star asks.
"Alright." Flower says. She creates another portal, in almost the same place as last time.
Star, with the bright-green rope from before tied securely around her waist, waves goodbye to you, Heart and Flower, and steps inside the portal, making a much louder hissing noise. 
Heart tightly grasps the rope in both of her hands.
"So..." She says, "We'll stay put here, and if Star doesn't come out after, what, five minutes?"
You nod.
"Yeah. Then we'll try to pull her out. And if that doesn't work, then we'll just have to go in ourselves!"

You take turns holding the rope for five minutes.
When Star doesn't exit the portal-thing after that time, Heart says,
"Star... Isn't the most reliable person ever. She might come back out in a few more minutes."
"Yeah." You say.

Once the 10th minute has passed, you're both beginning to worry.
"I had a feeling this would happen." You say.
"I'm going to try to pull her out." Heart says, "Could you help me?"
You nod. You station yourself behind Heart, and begin to pull the rope. It comes out easily... But it doesn't seem to end. You pull and pull at it, but the rope seems to have doubled, tripled, quadrupled in length.
"Uhh... I'm not sure this is working." Heart says once there's a small pile of rope sitting in front of the portal.
"Okay. Let's do this." You say, letting go of the rope to roll up your shirt sleeves.
Heart raises an eyebrow at you, but nods.
"Mhm!"