Derek woke up in the middle of the night. Meredith was coughing violently, her lips seemed to be a bit purple. Derek started rubbing her back and gave her a few tissues. she coughed into the tissue and saw she coughed up blood.

"Mer?!" Derek started panicking. He grabbed his phone and called Bailey, who's chief of surgery

"Bailey, it's Meredith. She's been sick.. no.. she's coughing up blood.. yes, we'll come in now" Derek said and hung up the phone. He helped her sit up in the bed and woke up the kids. Zola held Bailey and Ellis' hands and followed Derek, who was carrying Meredith, downstairs to the car. Derek quickly locked the door and buckled in the kids when Meredith was fighting to stay conscious but failed.

"Mama?" Ellis asked

"Mommy's sick, Ellie. We're gonna bring her to the hospital so the doctors can check her out"

"Is she okay?" Zola asked.

Bailey's snores filled the car as Derek had no idea how to respond. He couldn't tell his kids that their mommy's probably very sick. No one coughs up blood without a reason. Every 2-3 minutes he checked her pulse while driving to the hospital as fast as he could.

On their way to the hospital, Derek already called Alex. Jo and Alex would take care of the kids while Meredith got checked out.

Meanwhile, Meredith's breaths were unsteady and wheezy, a sigh of relief left Derek's body. They finally arrived, he stopped the car in the ambulance bay and got out to carry Meredith and put her onto a stretcher while Alex was taking care of the kids together with Jo.

They ran Meredith inside and placed an oxygen mask on her face before they brought her to CT.

...

Meredith was placed in a VIP room. She was stable for now. Her doctors have been checking out the results for the last couple of hours. Meredith was asleep while Derek held her hand. He kept a close eye on the rising of her chest, being terrified that she would stop breathing.

"Derek?" Teddy's voice was heard

"What's wrong with her?" He said on the edge of tears

Teddy, Bailey, Alex and Maggie entered the room

"Pulmonary fibrosis.." Maggie sighed

"Her lungs are scarring. We need to keep her on oxygen at all time" Bailey said

"How could this happen?" Derek started crying

"We'll need to do lots of other tests. As you know, pulmonary fibrosis usually goes together with other illnesses.." Teddy informed him

Derek nodded

"Page us when she's awake. It could take a while" Bailey said as the doctors left the room

"Damnit, Mer.. I should have noticed" He sighed

At that point, Amelia ran in

"Wh.. What happened?!" She gasped when she saw a pale and small Meredith lying in that hospital bed

...

Around noon, Meredith started to stir a bit. Derek's eyes glued on Meredith, wanting to be there when she woke up. She had a nasal cannula and several IV's to keep her hydrated. She'd lost a lot of weight, she always claimed to not be hungry.

"Hmm?" Meredith moaned before she burst out in a few strong coughs.

"Shh, you're okay" Derek said and gave her a glass of water

"What?" Meredith asked as she tried to sit up but her frail body was failing her.

Derek noticed and lifted up the head of the bed a bit so she could sit a bit more upright.

"Last night you started coughing up blood, I brought you in. Bailey and Teddy will be here soon" Derek said

"Kids? Where are the kids?" Meredith asked worried

"Jo is taking care of them, they're probably eating ice cream" Derek smiled, trying to hide his tears

"Grey, you're awake" Bailey smiled as she and Teddy walked in

"What's wrong with me?"

"Pulmonary fibrosis. We're gonna run a bunch of other tests to find the cause" Bailey said

"It might be nothing, but it's common to be combined with SARS, IPF, UIP or.." Teddy went quiet

"Or lung cancer" Meredith whispered, tears welling up in her eyes.

Derek immediately grabbed Meredith's IV free hand and kissed it.

"Can we do those tests now?" Meredith asked and Bailey and Teddy nodded.

...

Meredith was wheeled back to her room, she fell asleep during another CT scan. She was exhausted and now Derek finally knew why. When they got back in the room, she finally woke up again "Wanna see.. kids" She said, a bit short of breath. Derek placed the oxygen mask on her face

"You sure you have enough energy?" Derek asked her

"I.. wanna see.. my kids" She said as tears formed in her eyes, still out of breath.

"I'll page Alex" Derek said. He got up and fixed her gown and blankets. Setting her a bit more upright for when the kids would come in. She looked less pale than this morning but now Derek finally noticed how bad Meredith was doing these past weeks. They've been going on autopilot and never questioned Meredith's health situation.

Derek climbed on Meredith's bed and held her close for a couple of minutes when he saw Alex in the doorway. Derek got up, helped Meredith in a comfortable position and switched her back to her nasal cannula and called out for the kids.

"Mommy?" Zola questioned and slowly made her way to Meredith's bed and sat down on the left side of her mom

"Mom!" Bailey said and ran in. He sat down at Meredith's footend. He didn't question much.

"Come in, Ellie" Derek said as he walked toward the little girl who was hiding behind Alex' leg.

"Mommy?" She whispered

"I'm here, Ellie Belle.. Ellie, come to mama" Meredith said, clearly fighting for all the oxygen she could get

Ellie took Derek's hand and he placed the little girl on the other side of Meredith. All three kids cuddled their mom and soon all four of them fell asleep. The kids were clearly exhausted after last night and Derek could only focus on Meredith's breathing.