For Liseylou who prompted one of Gumnut-Logic's Daily Dose of Thunderbirds over on Tumblr.

It is a well-known fact that the eldest three Tracy's had a thing about their hair. As in, it must be perfectly groomed, not a strand out of place.

(It is the single reason Brains designed their helmets so big.)

Alan can remember watching them in front of the mirror for ages getting ready, whether for school or a date or just going out, there was no getting away with the fact that their hair was special.

They may have refined their styles over the years so that yes, all three and style and gel their hair in less than 30 seconds should the klaxon sound, but off duty, or on TI duty, that same level of care prevailed.

That's not to say that they had never done stupid stuff to their crowning glories. John would tell, only his are just as embarrassing, so this tends to be the one secret the blackmailer never will tell.

Alan didn't know most of the stories, being both too young and at home during the three's college years. Gordon vaguely knew there had been 'experiments' but had been so focused on swimming he couldn't remember them.

The eldest trio sighed in relief.

Until...

Looking through the attic for an old notebook that he was pretty sure he'd written down the plot for a good book, Alan stumbled upon a set of pictures wedged into one of Virgil's artist books.

Intrigued because the top one was definitely him, he looked though the ten pictures of him in various poses and in various activities. Once he reached the end Alan frowned and shuffled through them again.

One of these was not him.

In fact, one of these was definitely Virgil, but instead of his normal black locks he was sporting blonde hair. And worse, he had blonde eyebrows and blue eyes! Alan lost a good ten minutes just staring at the picture.

So unusual was it for Alan to be sat still for so long when he wasn't asleep or playing games, John appeared before him, concern written all over his face. Alan started when he appeared, but it was exactly what he needed – or rather who he needed.

'Alan, are you alright? You've been still for quite a while.' Alan nodded absentmindedly while he decided what he was going to do with this information. This was gold, worth a lot in his family!

'Er…yeah, I'm good.' John's eyes narrowed. Something was going on with his baby brother, he was sure. Alan had that gleam in his eye that he shared with Gordon when the two thought that they had one over on their elder brothers.

'Well, if you're sure,' he said, turning as if he was leaving. Right on cue Alan pipped up.

'I'm thinking to dying my hair black. What do you think?' And he was gratified for a momentary glimpse of a speechless spaceman. Alan was hard pressed not to smirk. 'After all, if I looked more like Virgil, maybe I'll be taken more seriously.' Ok, that good was thinking on my feet he congratulated himself.

'Um. Maybe you should talk to Virgil about that,' John said before really thinking that through. He inwardly cringed, hoping that Alan didn't pick up on that, but the kid was smart. He was a Tracy, after all.

'Why Virgil? Why can't I talk to you or Scott about it?' Alan flashed a look that should have telegraphed I am completely innocent and am asking a reasonable question. From John's frown he probably had said hahaha, I already know.

John took a little more time to answer. He really didn't want to drop Virgil into it any further than he already had, but judging from Alan's reaction, he already knew. Somehow. Time for some damage control.

'I am too busy to spend the time needed to discuss a matter like this, Alan, and Scott is in a meeting. Virgil, however, is free and is in the lounge.' And with that John winked out, damage control done as best he could.

Unperturbed by John's abrupt departure, or his blatant attempts to get out of the discussion, Alan took the picture with him up to the lounge, where Virgil was indeed sprawled out over one couch, eating popcorn and watching some movie.

Alan flopped down beside him and helped himself to a handful. They sat there for five minutes saying nothing. Alan thought he was very restrained. And he was timing it.

Waiting until Virgil had stuffed a handful into his mouth, he piped up: 'I'm thinking of dying my hair, Virgil. John said I should ask you.' He had no qualms about throwing John to the wolves.

Virgil was seized by a sudden coughing fit, and Alan dutifully thumped him on the back until the last piece of popcorn dislodged and his brother sat there, wheezing with tears flowing, trying to get his breath back.

Eventually he got himself under control and asked Alan to repeat himself. 'I'm thinking of dying my hair black. I think I'd look good black like you. What do you think?' What did he think? The immediate response was no way, but it wasn't his decision, and he remembered when Scott had wanted to dye his hair their mom had said the same thing. He shuddered with the memory and glanced at Alan.

The boy was far too eager and hanging off his every word, which told Virgil that the kid was up to something. They were well trained to spot 'younger brother is up to something that will get me into trouble' ever since Gordon had turned three. Alan was no different.

'Why black? Why not brown, or copper?' He had a sneaking suspicion, but Alan held his gaze and smiled.

'I think that blonde to black is a cool transition. And maybe I could get brown contacts so I could look like you!' Alan bounced, again, on the chair, trying to sound like he had just thought of this, but the look Virgil was giving him told him he wasn't succeeding.

It was the mention of contacts that did it for Virgil. Instantly transported to his senior year at high school, taking a leading role in The Sound of Music, he remembered how seriously he had taken the opportunity, dying his hair and eyebrows and wearing the contacts to appear as Frederick von Trapp did.

He held out his hand. There was no way Alan had seen any footage of the play, so there must be a picture somewhere, although Scott swore he had destroyed as many as he could. Both he and John had had their own hair embarrassments, so he knew the picture had not come from them. Most likely it was from something their Grandmother had saved. Even John wouldn't dare look through her stuff.

Alan obediently handed over the picture, grinning from ear to ear. Yep, he watched with delight as Virgil cringed, hand clenching enough to wrinkle the corner, and he listened with increasing mirth as Virgil explained why he had dyed his hair and worn contacts.

Promising Alan to do all his chores for a month as long as he didn't tell Gordon was worthwhile, Virgil mused, picture now secure from other prying eyes. It didn't stop him from watching the two carefully over lunch and dinner, but he did relax when nothing had happened by the time he went to bed

That all changed the next morning when his alarm clock played 'The Hills Are Alive With The Sounds of Music.'