After Tower Bridge the London Marathon course swings right along The Highway, once one of the capital's most notorious streets, and heads down towards Docklands. It is there that Mo Farah, if all has gone to plan, will ease up and bring his first experience of marathon running to a premature end at the halfway point.
It is all about the plan, a supposedly carefully laid one by Alberto Salazar, his coach and himself a former winner of the New York and Boston Marathons, to break his charge gently into the painful world of marathon running.
Come the halfway marker, which stands conveniently close to the hotel where he is spending his six-night stay in London, there will be no "Mobot" sign-off – from Farah at least – and he will hope to pull out as unobtrusively as possible, if that is feasible for a man who has become one of Britain's most recognisable sportsmen over the last nine months.
He wants to slip away out of what he calls respect for the event and his fellow athletes. They – the likes of Wilson Kipsang, the defending champion, and his Kenyan compatriot Geoffrey Mutai, the fastest marathon runner in history – have welcomed his place in the first half of the race. They believe it will only add to the atmosphere that escorts them around Farah's home town, while no doubt the first sighting of a future rival will add to their own competitive juices.
As part of this dry run – possibly the best-attended training run in history – Farah sees an opportunity to observe close up the men he will have to beat from next year. It is all part of the plan but it is one that has already attracted its critics. Paula Radcliffe, once his mentor and a runner who made a successful transformation from track to road, described it as "strange". Michael Johnson went further, writing in his column for The Times that Farah "risks ruining his reputation as his participation in only half the race looks like it is all about the money, and that leaves him open to criticism".
It is that whisper which has grown since his stunning feats spread over two unforgettable weekends in the Olympic Stadium last summer: Mo is in it for the money. He arrived in London on Wednesday and will fly home to his adopted home in Portland, Oregon, where he relocated with his wife and three children to train full-time with Salazar, on Tuesday, once he has fulfilled his obligations to the London Marathon organisers. On Monday he will face the media again to launch next year's race, the one in which he will go the distance.
He is being well paid for his 39 and a bit miles over two years, and his Olympic success will undoubtedly make him a rich man, as it will the likes of Jessica Ennis and Sir Bradley Wiggins. How much he is being paid for London is a closely guarded secret. It is into six figures, but what has so annoyed Farah are some of the sums being bandied around.
This afternoon he sat down to face the British media during a two-hour span of interviews with TV, radio and newspapers from around the world. He began by stating that he would not answer questions from the Daily Mail. Farah says they have written untruths about him and his wife.
Later he was asked about "tall-poppy syndrome". Carpe diem applies off the track or field of play. Careers are short, windows shut quickly. It is a delicate balancing act. Farah insisted it is not about the money.
"There are certain things the Daily Mail in particular write about that do annoy me," he said. "As an athlete, yes there are rewards, don't get me wrong, for what I achieve. If I get a reward I get a reward. But what really drives me is I hate losing. I want to win. I've trained so hard, put so much effort in. Yes there are rewards but that's for other people in my team to take care of. I never discuss other stuff."
He calls it the hobby that became his job, says competing for the sizeable cash rewards alone would be wrong and would not be a long-term motivation for taking to the track or the roads, let alone the hour upon hour, day after wearying day of training.
While this will be the first time he has begun the London Marathon, with its peculiar mix of sporting brilliance, celebration, endurance and men in rhino suits, it is not the first time he has featured on the day. He won the mini-marathon as a boy. He is adamant this occasion is special to him, whether it is over a mini-marathon, 13 miles or the full 26 miles and 385 yards. "It is the best in the world," he said.
Salazar has had to remind him not to get carried away, not to cross the halfway line, stick to the plan. That takes him to the world championships in Moscow in August where he will look to double up again in the 5,000m and the 10,000m before turning his attention to the marathon.
"I'm really excited," said Farah. "I said to Alberto: 'What happens if I feel great?' He said: 'No, your job is to do the halfway and that's it. If you feel good, that means we're doing a good training job'. But to get ready for Moscow I can't go on and destroy a couple of weeks of training. It's all planned – everything."
Farah's early bath
Reaching the halfway point in the London Marathon is odd. On one hand you're on cloud nine, having just crossed the iconic Tower Bridge. The boisterous crowds are thickest at the northern end of the bridge as you head down The Highway. Then, as you see the banner – "halfway" – you realise how tired you already are; and that you have to run the same distance over again. Unless you are Mo Farah. For him, the major headache will be getting through the packed throngs to a shower and a bite to eat. Organisers are refusing to say where exactly he will duck out, due to concerns for the other elite runners and crowd safety. But wherever he stops, there will be a commotion.