If you haven't seen the Christmas special this will include SPOILERS from that. I'm a typical Downton fan who wished Dan didn't leave. So here's my take on what would have happened after and how Mary communicates with her son about his father. Based on the Christina Perri song - A Thousand Years.

A Thousand Years

I have died everyday waiting for you

Darling don' be afraid I have loved you

For a thousand years

I'll love you for a thousand more

Mary sang the sweet melody, the words barely coming out of her mouth, without a tear following it down her cheek. Those words meant so much to her, every word represented her life six years ago. The words were her, were her life, her happiness and her love.

She gazed across the room, carefully using the extra material on her sleeve to brush the tears from her pale skin as she noticed her little boy was in his bed looking up at her. He had depended on his mother, like she had depended on him to get her through the tragic accident to with Matthew. His small eyes were similar to Matthew's, they showed you the world through the tiny pupil and gave you the warmth of his heart. She leant gently onto the edge of the bed, holding the small boy's hand in hers as she rubbed it gently to warm it. He giggled softly at his mother as she knew where his ticklish spot was on the back of his wrist.

"Mother" he giggled even louder, trying to hide how ticklish in fact he was finding it though he was failing incredibly as another whale came from out his mouth and the small pout that he so commonly now presented whenever he wasn't impressed with her was very much noticeable on his face.

"I'm very sorry" She laughed with her response, pretending she didn't know she was tickling him. She instantly stopping the tickling and helping her son get back into his bed, she pulled up the thin blankets that he had around him to help aid against the January breeze which was beginning to turn the weather into a cold blitz. She then carefully pulled the duvet up and under his chin and allowed the small tatted teddy bear to lay beside him. He wouldn't sleep without this small object, he found out that it was his father's when he was a boy and ever since he would never sleep without knowing his father was watching him. In fear of having nightmares he made sure that he held the item whenever he slept and the family knew if the bear ever went missing they would be the ones searching the house til early hours til it's been recovered.

Mary leant over to kiss her boy's forehead and wish him a good night before she got up and made her way towards the door of the room to get her own self ready for bed. "Mother?" The small boy's voice was heard, Mary carefully looked over her shoulder to see him sitting up in his bed and a concerned look rushed over his face.

"Yes my darling?" She replied softly, walking back into the room and leant next to him once again on the bed. She had been experiencing his questions just as she expected. He was now beginning to reach the age of understanding the world and its limitations and most importantly he was now realising the truth about the wondrous man his father was.

"I was looking round the house yesterday with Anna, and she told me not to go into your room, but I did and Anna tried to make me get out, but I didn't. I was trying to hide from Mr. Bates because we were playing and I hit my head on a box, I got it out and looked inside it was this dusty old book, with pictures and letters from father in, what was it?" His expression was so much like Matthew's in this instance, he looked intrigued to find out answers.

Mary had been expecting this day to come. She had always wanted to show her son this, but was waiting for the right time, the right time for him to realise who his father was, to realise the way he was created and to realise how important he was to his father and of course to her. She stood up, putting a finger in front of her to suggest to give her a second. She went into her own room, bending down on the right spot of the floor, lifting up the bedding from bed and pulling out the same box her son described and inside the same book full of pictures and letters from Matthew. She breathed heavily as she felt it back into her arms.

"This is the book you found?" Mary asked her son, he took one look at the dusty old book and nodded.

Mary sat down next to her son, allowing him to lay gently on her chest, she brushed the few stray hairs from his face and kissed his head before she began to gently open the book, revealing the first page. it was decorated in pictures from their wedding and had a main picture of them at the alter that had been taken just as they were announced husband and wife. She then read out the description below to her son.

"Dearest Mary, and my dearest unborn child,

This book is for both of you to cherish and forever see my undying love for you both,

These are full of pictures and memories of my life with you both,

and these are for you to understand the expectations of our lives,

I'd appreciate if you read a page per every night,

I hope you both never take love for granted,

all my love,

Your Matthew."

The tears were now flowing down Mary's cheeks, the bright colour of her eyes were almost glowing in the dark as she looked down towards her son to see his eyes we're welling up and felt the small boy hold onto his mother for his life. His body was warm and was tucked into her's. She hushed her son's cries and felt on closer to his body. It was just them.