The Doctor was ready to visit an old friend. Though he always was, though this time with importance. He needed to borrow K-9 just for a moment. He really hoped Sarah Jane wouldn't mind. He decided to leave a note explaining in case she wouldn't let him.
Eureka! He found K-9 in the corner charging. It would be simple, to the TARDIS and back, Sarah would never know. He fixed his bow tie and slicked his hair back. "Here we go old boy." praying the pet wouldn't make a sound.
"Who's there! We've got a vicious guard dog!" a young boy's voice came quietly in the living room. "No i told you stay back!" the boy whispered, to someone else.
"Daddy! There's someone in the house, Help!" a little girl was with him. Had he got the wrong house? No this is definitely K-9. Then why are there children here?
"What is it pumpkin? It's ok i am here" the doctor ducked under the couch, at the sound of the man's voice. Odd enough the voice sounded familiar.
"And i'm here to honey, what did you hear?" the woman's voice was gentle and familiar as well. The Doctor recognized Sarah instantly.
"Sarah Jane! it's just me, the Doctor! I've come to borrow K-9, if you don't mind that is" the Doctor was nervous but, stood up from behind the couch.
The lights were turned on. The Doctor gasped at the sight in front of him. Harry Sullivan! The imbecile! He was definitely older than the last time he'd seen him but, it was Harry. Holding an obviously scared little girl. She had to be three at the most; she looked just like Sarah. Then there was Sarah holding an equally frightened little boy. He was older than the girl maybe six or seven. He looked kind of like a mix of Harry and Sarah. His eyes widened at the realization.
"Doctor? Is it really you? Ah regeneration." Sarah sounded very relieved. She looked at the little boy in her arms and smiled. Indicating he didn't have to hide in her chest. "Luke, this is my old friend the Doctor. You've heard all about him." the little boy looked up at the Doctor and frowned.
"But he doesn't have a big scarf Mommy." Sarah and Harry laughed at the little boy. The Doctor stood as still as possible, still shocked by his discovery.
Sarah looked back at the Doctor and smiled radiantly. "Doctor this is our son Luke. And our Daughter Sky." she started to laugh quietly, when she noticed Sky had fallen asleep in Harry's arms.
"But Sarah, Harry I …" the Doctor was stuttering, he looked at his friends and their children. He regained his composure, fixed his bow tie and hoped to still borrow K-9.
Sarah and Harry put Luke and Sky to bed, not easily though. Then they told the Doctor how it had started in Aberdeen.