An Unshakeable Feeling
At this point, Tina knew she should probably stay home. She felt uneasy as they drove off, like there was a pit in her stomach. However, she kept quiet about it so she wouldn't ruin their plans...
She was Having a Heart Attack
When they got to the trail, Tina's legs started to go numb. Her breath felt sharp and she was dizzy and disoriented. She collapsed on the trail and realized she was having an unexpected heart attack.